Abstract: Provided is a rotation angle detection device configured to detect a rotation angle of a magnetic field generation source, based on a magnetic field in at least two directions detected by a magnetic field detection device. The rotation angle detection device includes a correction value calculation unit configured to calculate a correction value of the rotation angle; an angle output unit configured to output an angle output signal indicative of the rotation angle of the magnetic field generation source, based on a magnetic field detection signal to be output from the magnetic field detection device and the correction value; and a filter unit capable of selecting a first filter characteristic, which is to be used for outputting the angle output signal, and a second filter characteristic, which is to be used for calculating the correction value and is different from the first filter characteristic.

Abstract: To reduce the error in a rotational angle detected by a rotational angle detection apparatus, provided is a rotational angle detection apparatus that detects a rotational angle of a magnetic field generation source, including a magnetic field detection apparatus that detects magnetic field components in at least two directions, and outputs resulting detection data; a correction value calculating section that calculates correction values for correcting an angle error of the rotational angle, based on a steady-state error that does not depend on rotation of the magnetic field generation source; and an angle computing section that calculates the rotational angle of the magnetic field generation source based on the detection data and the correction values, and outputs an angle signal indicating the rotational angle.

Abstract: A process for fluidized catalytic cracking of heavy oils and production of hydrogen is described, comprising contacting steam and heavy oils with fluidized catalyst particles containing reduced iron at high temperatures, wherein a fluidized bed is formed such that the catalyst particles are fed from the bottom and withdrawn from the top of the fluidized bed and the fluidized bed is provided with a means for retarding the mixing rate of the catalyst particles in the vertical direction, to thereby generate a temperature difference between zones of the fluidized bed above and below said means, and use the upper zone for cracking of heavy oils and the lower zone for production of hydrogen. Catalyst particles withdrawn from the fluidized bed may be regenerated and recycled. Thus, light oils and hydrogen can be produced in high yields.