42 Technical consulting, design services for others, testing and technical analysis of disaster prevention systems comprised of computers for main system control and for remote monitoring section, antennas for monitoring and for GPS signal receiving, converters, radio frequency matrix switcher, receivers, transmitters, optical cables and coaxial cables; and software maintenance for disaster prevention systems comprised of computers for main system control and for remote monitoring section, antennas for monitoring and for GPS signal receiving, converters, radio frequency matrix switchers, receivers, transmitters, optical cables and coaxial cables