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Affiliation |
Engineering educational research section Information and Communication Technology Program |
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Related SDGs |
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USUZAKI SHOTARO
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Research Areas 【 display / non-display 】
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Informatics / Information security
Papers 【 display / non-display 】
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Shotaro Usuzaki, Kentaro Aburada, Hisaaki Yamaba, Mirang Park, Naonobu Okazaki
67 ( 3 ) 588 - 604 2026.3
Language：Japanese Publishing type：Research paper (scientific journal)
DOI： 10.20729/0002008648
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Takatsuka Kayoko, Usuzaki Shotaro, Yamaba Hisaaki, Aburata Kentaro, Okazaki Naonobu
KAGAKU KOGAKU RONBUNSHU 52 ( 1 ) 15 - 20 2026.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Society of Chemical Engineers, Japan
The spread of infectious diseases in the livestock industry results in severe economic losses and social disruption. This study focuses on the 2010 outbreak of foot-and-mouth disease (FMD) in Miyazaki Prefecture, Japan, and proposes a framework for quantitatively assessing farm-level susceptibility to infection through the construction of a Potential Infection Risk Index (λ). This index integrates multiple factors, including spatial proximity between farms, herd size, and livestock species. Statistical analysis reveals that λ values significantly differ between infected and uninfected farms, with the disparity widening as distance from the infection source decreases. These findings indicate that the spread of infection is strongly influenced by both geographic proximity and structural characteristics of farms. Furthermore, λ enables objective and quantitative identification of high-risk farms, supporting practical responses such as the prioritized allocation of limited disease control resources and the flexible application of hygiene management standards. A case study simulating farm relocation demonstrates that λ-based site selection effectively reduces infection risk, thereby validating the index as a practical and economically rational decision-support indicator. This approach also suggests the potential application of λ in long-term farm siting and structural planning. Additionally, the study envisions a comprehensive disease control support system centered on λ and its adjusted form (λ′), incorporating features such as risk visualization, hygiene-related corrections, tailored alerts and recommendations, and integration with administrative decision-making processes. Future work will focus on the development and implementation of such decision-support tools, with the ultimate goal of enhancing disease control efforts and contributing to the sustainable development of the livestock industry.
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Shotaro Usuzaki, Kosei Iwasa, Nobuya Takahashi, Kentaro Aburada, Hisaaki Yamaba, Mirang Park, Naonobu Okazaki
2025 9th International Conference on Information Technology (InCIT) 545 - 552 2025.11
Publishing type：Research paper (international conference proceedings) Publisher：IEEE
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Conjugate Gradient Based Multiplicative Update Rules for Nonnegative Matrix Factorization Reviewed
Nobuya Takahashi, Shotaro Usuzaki, Tetsuro Katayama, Masahiro Yokomichi, Kentaro Aburada, Naonobu Okazaki
2025 9th International Conference on Information Technology (InCIT) 639 - 644 2025.11
Publishing type：Research paper (international conference proceedings) Publisher：IEEE
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Evaluating the usability and security of the text-based CAPTCHA that asks to recognize hidden text with the help of human visual completion function Reviewed
Shotaro Usuzaki, Nobuya Takahashi, Taiki Kamada, Kentaro Aburada, Hisaaki Yamaba, Mirang Park, Naonobu Okazaki
IEICE COMMUNICATIONS EXPRESS 14 ( 12 ) 441 - 444 2025
Language：English Publishing type：Research paper (scientific journal)
Books 【 display / non-display 】
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Slow HTTP POST DDoS Attack Prevention Method that Monitors Payload Size and Number of Connections
Ozaki Y., Usuzaki S., Aburada K., Yamaba H., Park M., Okazaki N.（ Role： Sole author）
Lecture Notes on Data Engineering and Communications Technologies 2026
Book type：Scholarly book
The threat of distributed denial-of-service (DDoS) attacks has increased in recent years. In particular, the slow HTTP POST attack overwhelms web servers by maintaining slow connections with small payloads. Previous research has addressed this threat by monitoring the number of simultaneous connections and using programmable P4 switches. However, these approaches have shown limitations when facing distributed attacks from multiple IP addresses. In this study, we developed an improved defense method that monitors both the number of simultaneous connections and the payload size to more effectively identify a slow HTTP POST DDoS attack by capturing its characteristics. Experimental comparisons with existing methods demonstrated that connection-based monitoring alone is insufficient against distributed attacks, whereas our new method achieves better performance. Ultimately, implementing this method on a P4 switch is expected to reduce server load by blocking malicious traffic before it reaches the server, thereby enhancing the robustness of the entire system.
MISC 【 display / non-display 】
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An Attempt to Solve Fill in the Missing Letters CAPTCHA Using Generative AI. Reviewed
Hisaaki Yamaba, Shotaro Usuzaki, Kentaro Aburada, Masayuki Mukunoki, Mirang Park, Naonobu Okazaki
ICGEC (2) 1322 LNEE 385 - 395 2024
Publishing type：Rapid communication, short report, research note, etc. (scientific journal)
DOI： 10.1007/978-981-96-1535-3_38
Other Link： https://dblp.uni-trier.de/db/conf/icgec/icgec2024-2.html#YamabaUAMPO24
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Mirang Park, Zhaolin Chang, Shotaro Usuzaki, Kentaro Aburada, Naonobu Okazaki
CANDARW 293 - 299 2024
Publishing type：Rapid communication, short report, research note, etc. (scientific journal)
DOI： 10.1109/CANDARW64572.2024.00055
Other Link： https://dblp.uni-trier.de/db/conf/candar/candar2024w.html#ParkCUAO24
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Evacuation Support System for Tsunami Disasters that Considers Shelter Congestion. Reviewed
Hidetaka Nishi, Keita Nabeyama, Shotaro Usuzaki, Kentaro Aburada, Hisaaki Yamaba, Tetsuro Katayama, Mirang Park, Naonobu Okazaki
ICGEC (2) 1322 LNEE 51 - 62 2024
Publishing type：Rapid communication, short report, research note, etc. (scientific journal)
DOI： 10.1007/978-981-96-1535-3_7
Other Link： https://dblp.uni-trier.de/db/conf/icgec/icgec2024-2.html#NishiNUAYKPO24
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Usuzaki S., Aburada K., Yamaba H., Katayama T., Mukunoki M., Park M., Okazaki N.
Artificial Life and Robotics 27 ( 1 ) 2022.2
Publishing type：Rapid communication, short report, research note, etc. (scientific journal) Publisher：Artificial Life and Robotics
In the original publication of the article, on Figs. 4 and 5, “CNN” should read as “MLP”. In addition, under the section “4.2 Human and machine success rate”, on the paragraph “For evaluation of the machine success …”, in the following sentence “In the attack experiment, we applied the famous color …” CNN (Convolutional Neural Network) should be corrected as MLP (Multilayer perceptron). The correct sentence should read as “In the attack experiment, we applied the famous color constancy algorithm, Gray-World, Max-RGB, Gray-Edge [11], Second Derivative Gray-Edge, and MLP (Multilayer perceptron) to images that were saved in the experiment for the human success rate
Grant-in-Aid for Scientific Research 【 display / non-display 】
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深層学習を用いた筋電位による多要素個人認証の複数点測定による高精度化
Grant number：24K14948 2024.04 - 2027.03
独立行政法人日本学術振興会 科学研究費基金 基盤研究(C)
Authorship：Coinvestigator(s)
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AIによって高度化されたサイバー攻撃に対抗する次世代クラウドセキュリティ基盤の構築
Grant number：24K14917 2024.04 - 2027.03
独立行政法人日本学術振興会 科学研究費基金 基盤研究(C)
Authorship：Coinvestigator(s)
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透過的反射による人間の映り込みを高精度に検出するSNS投稿画像解析手法の開発
Grant number：23H05387 2023.04 - 2024.03
独立行政法人日本学術振興会 科学研究費補助金 奨励研究
Authorship：Principal investigator