Papers - OKAZAKI Naonobu
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MASUDA SHINYA, SUZUKI HIDEKAZU, OKAZAKI NAONOBU, WATANABE AKIRA
IPSJ Journal 47 ( 7 ) 2258 - 2266 2006.7
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Information Processing Society of Japan (IPSJ)
Threats to network security have become a serious problem, and encryption technologies for communications are an important issue these days. Although the security of IPsec ESP (a typical existing cipher communication technology) is strong, it has such problems that it can not be used in the environment where it coexists with NAT and firewalls, and that there also causes some degradation of throughput. For such reasons, ESP is used only for some limited applications such as VPN (Virtual Private Network). In this paper, we propose a new cipher communication protocol, called PCCOM (Practical Cipher COMmunication), that can verify the identity of the corresponding counterpart and assure the integrity of packets in the environment where it coexists with NAT and firewalls, without changing the format of the original packets. To confirm the effectiveness of PCCOM, we installed a trial system in FreeBSD, and confirmed the coexistibility with NAT and firewalls. We also measured its throughput, and good performance was confirmed owing to "no change" of the packet format.
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Takatsuka Kayoko, Usuzaki Shotaro, Yamaba Hisaaki, Aburata Kentaro, Okazaki Naonobu
KAGAKU KOGAKU RONBUNSHU 52 ( 1 ) 15 - 20 2026
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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視線入力を用いた画像選択と視線軌跡の特徴量による個人認証システムの評価
岩田一，常照林，臼崎翔太郎，油田健太郎，岡崎直宣，朴美娘
IPSJ SIG Technical Reports 2025-CSEC-110 1 - 8 2025.7
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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視覚の補完機能を利用した文字型CAPTCHAの提案
臼崎翔太郎，鎌田大貴，油田健太郎，山場久昭，片山徹郎，朴美娘，岡崎直宣
IPSJ SIG Technical Reports 2025-CDS-43 1 - 10 2025.5
Authorship：Last author Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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色の恒常性を利用したCAPTCHAの機械攻撃耐性の評価と分析
永井 麻裕, 臼崎 翔太郎, 油田 健太郎, 山場 久昭, 椋木 雅之, 岡崎 直宣
情報処理学会火の国情報シンポジウム2022論文集 ( B12-4 ) 1 - 8 2022.3
Authorship：Last author Language：Japanese Publishing type：Research paper (other academic)
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ウィンドウサイズ調整型監視によるリアルタイム性DDoS攻撃検知手法の検討
溝口 李佳, 臼﨑 翔太郎, 油田 健太郎, 山場 久昭, 岡崎 直宣
情報処理学会火の国情報シンポジウム2022論文集 ( B12-5 ) 1 - 8 2022.3
Authorship：Last author Language：Japanese Publishing type：Research paper (other academic)
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継続的な認証及び異なる歩行速度での二つの端末を用いた異常検知による歩行認証の研究
渡辺 一樹、油田 健太郎、岡崎 直宣、朴 美娘
IPSJ SIG Technical Reports 2021-SPT-41 ( 16 ) 2021.3
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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ウェアラブル端末を用いた覗き見耐性を持つジェスチャー認証手法の提案と評価
嘉藤 鴻介、渡辺 一樹、油田 健太郎、岡崎 直宣、朴 美娘
IPSJ SIG Technical Reports 2021-SPT-41 ( 17 ) 2021.3
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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分散機械学習における勾配の 異常検知を用いたブロックチェーンシステムの提案とその実現性の評価
長友 誠、油田 健太郎、岡崎 直宣、朴 美娘
IPSJ SIG Technical Reports 2020-CSEC-88 ( 22 ) 2020.3
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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スマー トウォッチにおけるジェスチャを用いた個人認証方式の提案と評価
長友 誠、小関朋奈，渡辺 一樹、油田 健太郎、岡崎 直宣、朴 美娘
2020 Symposium on Cryptography and Information Security (SCIS2020) ( 1E2-1 ) 2020.1
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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ブロックチェーンを用いた不正ログイン対策の検討
藤 竜成, 臼崎 翔太郎, 油田 健太郎, 朴 美娘, 白鳥 則郎, 岡崎 直宣
CSS2019 1336 - 1342 2019.10
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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ブロックチェーンを用いた分散機械学習におけるパラメータ異常検知システムの提案
長友 誠, 油田 健太郎, 岡崎 直宣, 朴 美娘
CSS2019 1343 - 1348 2019.10
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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複数ウィンドウサイズの効率的監視によるバースト形態に依らないDDoS攻撃検出手法の検討
臼崎 翔太郎, 油田 健太郎, 山場 久昭, 朴 美娘, 岡崎 直宣
情報処理学会マルチメディア，分散，協調とモバイルシンポジウム（DICOMO2019）論文集 495 - 504 2019.7
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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スマートロックにおける異常検知を用いた二つの端末の加速度による歩行認証の提案 Reviewed
渡辺 一樹, 長友 誠, 油田 健太郎, 岡崎 直宣, 朴 美娘
情報処理学会マルチメディア，分散，協調とモバイルシンポジウム（DICOMO2019）論文集 1155 - 1160 2019.7
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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マーカーを用いたカメラと加速度センサによるセキュアデバイスペアリング手法の評価
長友 誠, 油田 健太郎, 岡崎 直宣, 朴 美娘
IPSJ SIG Technical Reports IPSJ-CSEC-85 ( 7 ) 2019.5
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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スケジュール・ネットワーク全体に分散するフロートの包括的評価
高塚 佳代子，富田 旋，高橋 尚己，佐藤 知一，岡崎 直宣
化学工学会第84年会講演予稿集 I-206 2019.3
Language：Japanese Publishing type：Research paper (other academic)
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スマートホーム内のIoT機器を対象としたサイバー攻撃への耐性評価
坂本 憲理，長友 誠，岡崎 直宣，朴 美娘
IPSJ SIG Technical Reports 2019-SPT-32 ( 24 ) 1 - 8 2019.2
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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覗き見耐性を持つ小型タッチスクリーン端末における個人認証方式の提案
長友 誠，渡辺 一樹，油田 健太郎，岡崎 直宣，朴 美娘
2019 Symposium on Cryptography and Information Security (SCIS2019) 3E4-2 2019.1
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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スライドウィンドウを利用したエントロピー手法による軽量なDDoS攻撃検知手法の検討
臼崎 翔太郎，山場 久昭，油田 健太郎，岡崎 直宣
IPSJ SIG Technical Reports 2018-ITS-75 ( 7 ) 1 - 3 2018.11
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)
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青島地区における避難者の歩行速度を考慮した災害時の避難行動に関するシミュレーション
本田 佳鈴，山場 久昭，油田 健太郎，岡崎 直宣
IPSJ SIG Technical Reports 2018-ITS-75 ( 19 ) 1 - 8 2018.11
Language：Japanese Publishing type：Research paper (conference, symposium, etc.)