about me

My name is TOKUNAGA Hiroyuki (徳永 拓之). TOKUNAGA is the family name, Hiroyuki is the first name.

My ultimate goal is to make machines more intelligent. To achieve this goal, I am strongly interested in accelerating machine learning based software from both algorithm and implementation perspectives.


My e-mail address is {family name}.{first name}@gmail.com.


These books are written in Japanese.

  • Many Authors. Encyclopedia of Artificial Intelligence (人工知能学大事典). Kyoritsu Shuppan Co., Ltd. 2017. ISBN: 978-4-320-12420-2. (responsible item: kana-kanji conversion (仮名漢字変換))
  • Yuya Unno, Daisuke Okanohara, Seiya Tokui and Hiroyuki Tokunaga. Online Machine Learning (オンライン機械学習). Kodansha Ltd. 2015. ISBN: 978-4061529038.
  • Hiroyuki Tokunaga. The Art of Japanese Input Methods (日本語入力を支える技術). Gijutsu Hyoron Co., Ltd. 2012. ISBN: 978-4774149936.

Social Activities

Open Source Software

  • Micter: A machine learning based word splitter, which optimizes hinge loss with FOBOS (Duchi, 2011).
  • Rakai: A document classifier written in Go. Classification algorithm is NBSVM (Wang, 2012).
  • Dary: An implementation of (dynamic) double array trie.