The propagation characteristics of the crank-tunnel with reflectors

In underground environments, communicability is vital in emergency cases such as fires, as well as in routine management operations. In a disaster, the lines of the wire communication system may be damaged. Therefore, a simple wireless device is necessary for the preservation of public safety. The present study aims at establishing a basis for solving such problems. The authors have analyzed the propagation characteristics of the crank-tunnel. To solve such a boundary value problem, they have introduced the boundary-element method and the surface impedance approximation. Owing to the presence of the reflector, radio communication characteristics in crooked tunnels are improved.<
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