Ajou University, Mar. 16--22 in 2014 (supported by Suyoung Choi).
Fudan University Dec. 19--24 in 2013 (supported by Prof. Zhi Lu).
University of Manchester, May 9--10 in 2013 (supported by Prof. Nigel Ray); Feb. 5-- Apr. 7 in 2012 (supported by the JSPS Institutional Program for Young Researcher Overseas Visits "Promoting international young researchers in mathematics and mathematical sciences led by OCAMI". The host professor was Prof. Nigel Ray).
Kings College in London, April 29--May 11 in 2013 (supported by the JSPS Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation "Deepening and Evolution of Mathematics and Physics, Building of International Network Hub based on OCAMI". The host professor was Hironao Kato).
Princeton University Feb. 15--22 in 2013, (supported by Prof. Tony Bahri in Rider University).
University of Toronto Aug. 22--30 in 2015 as a visitor; Oct. 1 in 2012--Sep. 30 in 2013 as a visiting professor (supported by the JSPS Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation "Deepening and Evolution of Mathematics and Physics, Building of International Network Hub based on OCAMI". The host professor was Prof. Yael Karshon); May 9--Jun. 20 in 2005 as a visiting student (supported by the grant of JSPS fellowship DC1. The host professors were Prof. Lisa Jeffery and Prof. Megumi Harada).
Moscow State University, Sep. 12--27 in 2012 (supported by the bilateral program between Japan and Russia: "Topology and geometry of torus actions and combinatorics of orbit quotients". The host professor was Taras Panov).
Adam Mickiewicz University, Sep. 9--12 in 2012 (supported by Prof. Krzysztof Pawalowski).
Max Plank Institute for Mathematics, Mar. 1--7 in 2012 (supported by the JSPS Institutional Program for Young Researcher Overseas Visits "Promoting international young researchers in mathematics and mathematical sciences led by OCAMI". The host professor was Michael Wiemeler).
KAIST, Jan. 23-- 26 in 2019 (supported by Jongbaek Song); Mar. 5-- 10 in 2018; Mar. 12-- 18 in 2017; Jan. 18-- 29 in 2016; Mar. 29-- Apr. 11 in 2015; Dec. 24 in 2011-- Jan. 6 in 2012 (supported by Prof. Dong Youp Suh).
Osaka City University, Aug. 1--10 in 2011; Nov. 18--Dec. 12 in 2010; Mar. 23--28 and Dec. 6--13 in 2009 (supported by Prof. Mikiya Masuda).