Researcher

Masashi Sugiyama

Masashi Sugiyama researches statistical machine learning under limited and imperfect information. He earned his doctorate in 2001, became a University of Tokyo professor in 2014 and began directing RIKEN AIP in July 2016. He coauthored the 2017 positive-unlabeled learning paper with a non-negative risk estimator. His later work includes a 2022 book on weak supervision and research on complementary labels and test-time adaptation. He directs RIKEN’s Imperfect Information Learning Team.

Works
1,005
Citations
21,047
h-index
67

Publication numbers from OpenAlex, as of 14 October 2026.

Photo of Masashi Sugiyama

Timeline

  1. 2001–2014

    A statistical learning career

    Sugiyama received his doctoral degree at Tokyo Institute of Technology in March 2001. He became a University of Tokyo professor in October 2014. His research centers on statistical machine-learning theory and algorithms.

  2. July 2016

    Leading RIKEN AIP

    He began directing RIKEN’s Center for Advanced Intelligence Project in July 2016. The Imperfect Information Learning Team studies accurate learning when large or complete datasets are unavailable.

  3. 2017

    Learning from positive and unlabeled data

    Sugiyama coauthored a method for positive-unlabeled learning with Ryuichi Kiryo, Gang Niu and Marthinus du Plessis. The paper introduces a non-negative risk estimator. It addresses a setting in which training data includes known positive cases and unlabeled examples.

  4. 2022–2024

    Weak supervision and changing data

    His team coauthored the 2022 book Machine Learning from Weak Supervision. Later papers address complementary labels and adaptation in changing test environments. These studies continue the documented focus on learning from imperfect information.

Sources and credits

Photo: www.riken.jp; Masashi Sugiyama profile photograph; creator not stated. License: Not stated by source. Source: riken.jp. Cropped to a square and resized. Ask us to remove or replace this photo.

  1. Masashi Sugiyama: curriculum vitae ms.k.u-tokyo.ac.jp. Checked 13 October 2026.
  2. RIKEN: Imperfect Information Learning Team riken.jp. Checked 13 October 2026.
  3. Positive-Unlabeled Learning with Non-Negative Risk Estimator arxiv.org. Checked 13 October 2026.