A pressure relief valve for releasing pressure from a system, which pressure relief valve typically includes a valve housing provided on a pressure relief conduit which receives pressure from the system. The write voltage applying circuit applies a write compensating voltage, which has a polarity opposite to that of the voltage applied on the both ends of the unselected memory cells other than the selected memory cell, on both ends of the unselected memory cells, while the write voltage is applied to the selected memory cell. The title key confers rights from the content owners to the user to play and copy the content for personal use. A shaper generates a pulse indicative of energy of the radiation illuminating the direct conversion material based on the amplified compensated signal.