A method of determining a rotor angle in a drive control for a motor, comprising the steps of determining a rotor magnetic flux in the motor; estimating the rotor angle on the basis of the rotor magnetic flux; and correcting the estimated rotor angle on the basis of reactive power input to the motor. These parameters include detector quantum efficiency, channel transmittance and pulse spacing. Preferably, the pallet is delivered to the ocean floor in advance by crane with the reel-mounted sensor array cables being deployed later by ROV. The arrival determining unit determines whether the capsule endoscope has reached the stomach or not. Expression of GrB-NIC is also observed in malignant cells of other types as well as in normal non-immune cells upon cell differentiation, especially in differentiating and differentiated neural cells.