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Publication
Featured researches published by Hisao Yamamoto.
Applied Optics | 1978
Hisao Yamamoto; Haruo Ogiwara
The switch uses a V-grooved connecting device. The mechanism is suitable for a large switch, which is desirable for an optical switching system. A moving fiber is inserted into one of the radially arranged V grooves using the elastic bending force as the drive current. The insertion condition, which realizes stable connection and high durability, is discussed. Switch structure and experimental results are described. Insertion loss was 0.33 dB, and the variation in transmissivity was 3%.
IEEE Transactions on Communications | 1983
M. Yokoyama; Hisao Yamamoto; M. Kajiwara
A multi-bit-rate substitute-communication system (MSCS) is an efficient means to achieve higher call-carrying capacity in a congested network. When a trunk line is congested with a large amount of traffic, MSCS makes subscribers communicate by a lowerbit-rate medium, even though they request higher-bit-rate forms. This limitation is made when the number of idle basic channels is less than or equal to the predetermined system constant. This paper describes the control method, traffic characteristics, and concrete traffic design method, using a dual-bit-rate class (64 kbits/s, 8 kbits/s) model. It is found that the MSCS carries about five times as many calls as a conventional network without the MSCS.
Archive | 1989
Hisao Yamamoto; Kenichi Mase; Akiya Inoue; Hiroo Itou; Masato Suyama; Yoshitaka Hoshi
IEEE Transactions on Communications | 1983
Kenichi Mase; Toyofumi Takenaka; Hisao Yamamoto; Masaaki Shinohara
Modelling the Innovation | 1990
Akiya Inoue; Hisao Yamamoto
Archive | 1978
Haruo Ogiwara; Hisao Yamamoto
Electronics and Communications in Japan Part I-communications | 1982
Kenichi Mase; Masaichi Kajiwara; Hisao Yamamoto; Masaaki Shinohara
Archive | 1981
Kenichi Mase; Hisao Yamamoto
Electronics and Communications in Japan Part I-communications | 1981
Hisao Yamamoto; Masaaki Yokoyama; Haruo Ogiwara
Archive | 1989
Yoshitaka Hoshi; Akiya Inoue; Hiroo Itou; Kenichi Mase; Masato Suyama; Hisao Yamamoto