A Study on Propagation Characteristics of Spread Spectrum Sound Waves Using a Band-Limited Ultrasonic Transducer. - Akio Yamane; Taketoshi Iyota; Yongwoon Choi; Yuzuru Kubota; Kazuhiro Watanabe (J. Robotics Mechatronics, 2004)

Measurement accuracy on indoor positioning system using spread spectrum ultrasonic waves. - Akimasa Suzuki; Taketoshi Iyota; Yongwoon Choi; Yuzuru Kubota; Kazuhiro Watanabe; Akio Yamane (ICARA, 2009)