Abstract: A monitoring system according to the present disclosure includes: an optical fiber (10) configured to sense a peripheral environmental state, a monitor's terminal (40), a receiving unit (20) configured to receive an optical signal containing information indicating the environmental state from the optical fiber (10), a detecting unit (32) configured to detect at least one of an accident and an incident, based on the information indicating the environmental state, being included in the optical signal, and a broadcasting unit (33) configured to broadcast that the accident or the incident has occurred to the monitor's terminal (40) when the detecting unit (32) determines that the accident or the incident has occurred.

Abstract: A voltage-driven power semiconductor device includes a voltage-driven IEGT chip, a collector electrode plate, an emitter electrode plate, and an inductance material. The collector electrode plate is connected to the collector of the IEGT chip, and press-contacts the IEGT chip from its collector side. The emitter electrode plate press-contacts the IEGT chip from its emitter side. The inductance material has an inductance component and connects the emitter of the IEGT chip and the emitter electrode plate. In the voltage-driven power semiconductor device having this arrangement, an induced electromotive force is generated in the inductance material arranged between the emitter of the IEGT chip and the emitter electrode plate. This induced electromotive force can suppress a steep current change (di/dt) upon an OFF operation, and can further suppress a steep voltage change (dv/dt) caused by the current change (di/dt).