Kohei Ozaki / 小嵜耕平

Kohei Ozaki (a.k.a. @smly) is a Software Engineer at Ubie. My specialties are around data and machine learning. I love to discover knowledge and hidden values in data.

保険/金融/広告ほか様々な事業でデータ分析や研究開発などの業務を 10 年以上経験してきました。現在はUbie株式会社でソフトウェアエンジニアをしています。またTURING株式会社でフェローをしています。

Data Science Competitions

I am a Kaggle competitions' Grandmaster (an honor to top competitors with outstanding data science skills) with 19 kaggle competitions' gold medals. My highest kaggle rank is 4th of 530,000+ data scientists on 2016 April.

🥇 1st place, Hotel-ID to Combat Human Trafficking (2021)
🥇 1st place, SpaceNet5: Automated Road Network Extraction (2020)
🥇 1st place, Google Landmark Retrieval Challenge 2019 (2019)
🥇 1st place, SpaceNet2: Building Detection v2 (2018)
🥇 1st place, Springleaf Marketing Response Competition (2015)
🥇 1st place, ACM/KDD, KDDCup 2015 - MOOC dropout prediction (2015)

Programming Contests

ACM/ICPC is an annual multi-tiered competitive programming competition among the universities of the world. I joined this contest with my friends at Tokyo University of Science and advanced to the Asia Regional Contest.

2014-07: ICFP Programming Contest 2014 (6th in the Lightning Round)
2008-10: ACM/ICPC Asia Regional Contest 2008, Aizu.
2007-11: ACM/ICPC Asia Regional Contest 2007, Tokyo.

Interview / Media

📄 2022-01-31 "xView3 Winners Announced" -- The Defense Innovation Unit (DIU) and Global Fishing Watch (GFW)
📄 2021-09-30 "Meet The Winners of the Overhead Geopose Challenge" -- DRIVENDATA Labs
📄 2018-04-03 "業務時間のKaggle参加を推奨する新制度導入" -- DeNA Corporate Announcements
📄 2016-09-05 "課題を正しく設定し、チームで協調することが重要" -- DataScience Society JOURNAL
📄 2016-02-11 "Software Competition Helps Researchers Tell Right Whales Apart" -- NOAA Fisheries, Northeast Fisheries Science Center

Publications

Google Scholar

📄 Shuhei Yokoo, Kohei Ozaki, Edgar Simo-Serra, Satoshi Iizuka, "Two-stage discriminative re-ranking for large-scale landmark retrieval", 2020. [arxiv]
📄 Yusuke Niitani, Toru Ogawa, Shuji Suzuki, Takuya Akiba, Tommi Kerola, Kohei Ozaki, Shotaro Sano, "Team PFDet's Methods for Open Images Challenge 2019", 2019. [arxiv]
📄 Kohei Ozaki, Shuhei Yokoo, "Large-scale landmark retrieval and recognition under a noisy and diverse dataset ", 2019. [arxiv][github]
📄 Kohei Ozaki, Masashi Shimbo, Mamoru Komachi, Yuji Matsumoto, "Mutual k-Nearest Neighbor Graph Construction in Graph-based Semi-Supervised Classification ", Tra nsactions of the Japanese Society for Artificial Intelligence, 2013.
📄 Kohei Ozaki, Masashi Shimbo, Mamoru Komachi, Yuji Matsumoto, "Using the mutual k-nearest neighbor graphs for semi-supervised classification on natural language data", Proceedings of the fifteenth conference on computational natural language learning, 2011.
📄 Asad Habib, Masayuki Asahara, Yuji Matsumoto, Kohei Ozaki, "JaPak IEOU: Japan-Pakistan's Input English Output Urdu a case sensitive standard input system for Perso-Arabic script clients", IEEE 2010 International Conference on Information and Emerging Technologies, 2010.

Lectures

🎓 2019-09-19, "情報科学特論2019", 首都大学東京 (集中講義・演習、首都大学東京)
🎓 2018-07-24, "ビッグデータ解析" (ゲスト担当分、大阪大学大学院情報科学研究科)
🎓 2015-10-15, "競技データマイニングにおけるテクニックと動向", 鹿島研究室公開セミナー, 京都大学

Talks / Presentations

🦊 2019-06-16 "Large-scale Landmark Retrieval/Recognition under a Noisy and Diverse Dataset", CVPR'19 WS, Las Vegas
🦊 2018-05-19 "データ分析コンテストの解答から学ぶ", PyCon mini Osaka, 大阪
🦊 2018-03-03 "データ分析コンテストの勝者解答から学ぶ", ステアラボ人工知能シンポジウム 2018, 千葉工業大学
🦊 2018-06-18 "Local vs Global Descriptor? Relevance Scoring with using Both", CVPR'18 WS, Salt Lake City
🦊 2017-10-20 "データ分析コンテストの技術と最近の進展", 第14回ステアラボ人工知能セミナー, 千葉工業大学
🦊 2017-07-29 "画像処理コンペティションにおける技術とワザ", Kaggle Student Meetup by Sansan
🦊 2016-09-09 "Python とデータ分析コンテストの実践", FIT2016 第15回情報科学技術フォーラム, 富山大学
🦊 2016-07-04 "実験の再現性と効率化の話（Docker と Serialization 周辺）", ビッグデータ基盤技術勉強会, 筑波大学
🦊 2016-03-05 "Workflow, Serialization & Docker for Kaggle", Kaggle Tokyo Meetup #1, 東京
🦊 2016-02-01 "国際チームにおけるモデリング手法とチームガイドライン", 情報処理学会誌 (2016年2月号) 小特集
🦊 2015-10-27 "Techniques (Tricks) for Data Mining Competition", BrainPad 社内講演
🦊 2015-10-23 "データマイニングコンテストにおけるテクニック", PyData.Tokyo Meetup #6
🦊 2015-08-09 "3-Stage Ensemble and Feature Engineering for MOOC Dropout Prediction", KDD'15 workshop. (発表のみ)
🦊 2013-11-30 "InfluxDB & LevelDB Inside-out", モニタリングカジュアル#5, 京都
🦊 2012-06-09 "Distributed Graph System & Related Topics", TokyoWebMining18