Masato Koyama

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—This paper proposes position and force control of a screw motor with power-saving axial-gap displacement adjustment. The motor has a helical-shape mover, which moves in a helical-shape stator without contact. Due to the fabrication process, the actual helical shapes of the mover and the stator are not completely uniform and the air-gap length between the(More)
The catfish (Synodontis nigriventris) has a unique habitat of keeping an upside-down posture under normal gravity. We examined its postural control under pseudomicrogravity generated artificially, and the effect of unilateral labyrinthectomy on the postural control. The stable swimming posture under pseudomicrogravity was observed in the upside-down(More)
In general, most fishes maintain a swimming posture with the dorsal side towards the water surface under normal gravity condition. In contrast to normal fishes, a catfish Synodontis nigriventris, shows a unique postural control. The catfish keeps its posture with the ventral side towards the water surface and the dorsal side towards water bottom under(More)
The upside-down catfish Synodontis nigriventris has a unique habit of swimming and resting upside-down in free water. This behavior leads to the assumption that the catfish has a specific gravity information processing system. We examined the postural control behaviors in the catfish under clinorotation which is usually used for producing(More)
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