Hiroyuki Katsukawa

TL;DR: In this paper, a helmet with two-way radio communication faculty including a cap-like outer shell made of hard and electrically insulating plastic material, an ear-pad member secured to one side edge of the outer shell, a transmitter unit arranged in a top recess formed in an outer surface of the shock absorbing member at its top portion, a receiver unit arranged on an inner surface of an earpad member, a battery unit arranged inside a side recess forming in the outer surface, opposite to a side on which the ear pad member is secured.

TL;DR: In this article, a work helmet for effecting an intercommunication between workers as well as between a central control room and respective workers, especially used for informing each workers of guide information adequate for emergency escape when a disaster occurs is disclosed.

TL;DR: In this article, the authors have studied feasible basic circuit configurations and control methods required to apply electric double-layer capacitors as an energy storage element in output-power leveling systems for solar cells or windmill power generators, and in uninterruptible power supply systems.

TL;DR: In this article, the optical current sensors having opto-magnetic elements and optoelectric field elements on respective conductors of the transmission line were used to detect a fault current and fault voltage on the basis of the Faraday's effect and Pockel's effect.

TL;DR: In this paper, an excellent optical fiber built-in type composite insulator including at least two insulator bodies each having a penetration bore, at least one optical fiber inserted in the penetration bores, and sealing structures for the penetration bore of the insulator body and for a joining layer of opposing end surfaces of adjacent insulators bodies, which effectively prevents leakage of inner silicone grease, bending and breakage of the optical fiber, leakage of electric current along the penetration body, short circuited trouble, and destruction of the INSulator bodies, improves joining strength of the opposing end