Akio Iso - Academia.edu (original) (raw)
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Papers by Akio Iso
Journal of the Japan Society for Aeronautical and Space Sciences, 1992
IEE Proceedings F Communications, Radar and Signal Processing, 1984
The characteristics of advanced digital transmission systems were measured using newly developed ... more The characteristics of advanced digital transmission systems were measured using newly developed small earth stations and a K-band (30/20 GHz) and C-band (6/4 GHz) communication satellite. Satellite link performance for data, facsimile, video and packet switching information transmission at bit rates ranging from 6.4 kbit/s to 6.3 Mbit/s have been confirmed, using a small K-band (30/20 GHz) earth station and a demandassignment time division multiple access (DA-TDMA) system. A low-capacity omni-use C-band (6/4 GHz) terminal experiment has verified a telephone channel transmission performance by spread-spectrum multiple access (SSMA). Single point to multipoint transmission characteristics of the 64 kbit/s data signals from the computer centre were tested using a receive-only 4 GHz earth terminal. Basic satellite link performance was confirmed under clear-sky conditions; however, evaluation of the satellite link is also described based on rain attenuation and sun-transit interference data. Precise satellite orbit and attitude keeping experiments were carried out to obtain precise satellite antenna pointing accuracy for development of K-band earth stations that do not require satellite tracking equipment. Precise station keeping accuracy of 0.02 degrees was obtained.
This report presents the outline of the MONOBEC machine experimentally made for an assumed single... more This report presents the outline of the MONOBEC machine experimentally made for an assumed single-track tunnel as well as the results of cutting and filling tests made on a mock ground. The MONOBEC (Mono-Bent-Cutter) method is being developed as a pre-lining method to prevent surface settlements and maintain the stability of the working face when a tunnel is driven by NATM through urban unsolidified grounds in Japan. The features of this method are as follows: 1) A solt is pre-cut ahead of the face and exactly along the tunnel profile using an S-shaped bend-type chainsaw cutter; and 2) Shooting concrete into the slot, a continuous concrete lining is formed.
Journal of the Japan Society for Aeronautical and Space Sciences, 1989
Journal of the Japan Society for Aeronautical and Space Sciences, 1998
Journal of the Japan Society for Aeronautical and Space Sciences, 1993
Acta Astronautica, 1983
Attitude reorientation maneuvers were conducted three times on the transfer orbit to obtain the a... more Attitude reorientation maneuvers were conducted three times on the transfer orbit to obtain the apogee kick motor firing attitude of the Medium Capacity Geostationary Communication Satellite for Experimental Purposes (CS) on the third apogee. After two attitude and five orbit maneuvers on the drift orbit, the CS attained geostationary orbit with station keeping accuracy of +0.1 ° seven days after launch.
Journal of the Japan Society for Aeronautical and Space Sciences, 1992
IEE Proceedings F Communications, Radar and Signal Processing, 1984
The characteristics of advanced digital transmission systems were measured using newly developed ... more The characteristics of advanced digital transmission systems were measured using newly developed small earth stations and a K-band (30/20 GHz) and C-band (6/4 GHz) communication satellite. Satellite link performance for data, facsimile, video and packet switching information transmission at bit rates ranging from 6.4 kbit/s to 6.3 Mbit/s have been confirmed, using a small K-band (30/20 GHz) earth station and a demandassignment time division multiple access (DA-TDMA) system. A low-capacity omni-use C-band (6/4 GHz) terminal experiment has verified a telephone channel transmission performance by spread-spectrum multiple access (SSMA). Single point to multipoint transmission characteristics of the 64 kbit/s data signals from the computer centre were tested using a receive-only 4 GHz earth terminal. Basic satellite link performance was confirmed under clear-sky conditions; however, evaluation of the satellite link is also described based on rain attenuation and sun-transit interference data. Precise satellite orbit and attitude keeping experiments were carried out to obtain precise satellite antenna pointing accuracy for development of K-band earth stations that do not require satellite tracking equipment. Precise station keeping accuracy of 0.02 degrees was obtained.
This report presents the outline of the MONOBEC machine experimentally made for an assumed single... more This report presents the outline of the MONOBEC machine experimentally made for an assumed single-track tunnel as well as the results of cutting and filling tests made on a mock ground. The MONOBEC (Mono-Bent-Cutter) method is being developed as a pre-lining method to prevent surface settlements and maintain the stability of the working face when a tunnel is driven by NATM through urban unsolidified grounds in Japan. The features of this method are as follows: 1) A solt is pre-cut ahead of the face and exactly along the tunnel profile using an S-shaped bend-type chainsaw cutter; and 2) Shooting concrete into the slot, a continuous concrete lining is formed.
Journal of the Japan Society for Aeronautical and Space Sciences, 1989
Journal of the Japan Society for Aeronautical and Space Sciences, 1998
Journal of the Japan Society for Aeronautical and Space Sciences, 1993
Acta Astronautica, 1983
Attitude reorientation maneuvers were conducted three times on the transfer orbit to obtain the a... more Attitude reorientation maneuvers were conducted three times on the transfer orbit to obtain the apogee kick motor firing attitude of the Medium Capacity Geostationary Communication Satellite for Experimental Purposes (CS) on the third apogee. After two attitude and five orbit maneuvers on the drift orbit, the CS attained geostationary orbit with station keeping accuracy of +0.1 ° seven days after launch.