Characteristics of Unmaintainable Source Code in Software Development by Multiple Organizations. - Ryo Ishizuka; Naohiko Tsuda; Hironori Washizaki; Yoshiaki Fukazawa; Shunsuke Sugimura; Yuichiro Yasuda (BCD, 2018)

Categorizing and Visualizing Issue Tickets to Better Understand the Features Implemented in Existing Software Systems. - Ryo Ishizuka; Hironori Washizaki; Yoshiaki Fukazawa; Shinobu Saito; Saori Ouji (IWESEP, 2019)

Effects of Software Modifications and Development After an Organizational Change on Software Metrics Value. - Ryo Ishizuka; Naohiko Tsuda; Hironori Washizaki; Yoshiaki Fukazawa; Shunsuke Sugimura; Yuichiro Yasuda (IEICE Trans. Inf. Syst., 2019)

Outdoor positioning system using received signal strength indicator based on reliability. - Bingjun Li; Ryo Ishizuka; Kaidi Wang; Shigeyuki Tateno (SICE, 2021)

Multi-floor Positioning Method based on RSSI in Wireless Sensor Networks. - Huizi Zhang; Hayato Fukunaga; Ryo Ishizuka; Tong Li; Shigeyuki Tateno (SICE, 2022)