Abstract: A spot size converter includes a first optical waveguide, and a second optical waveguide. The first optical waveguide has a first tapered portion. The first tapered portion extends in a direction in which the first optical waveguide extends, and is thicker with decreasing distance from an end portion of the first optical waveguide and is thinner with decreasing distance from the second optical waveguide. The second optical waveguide is separated from the first tapered portion and has a second tapered portion. The second tapered portion extends in a direction in which the second optical waveguide extends, and is thinner with decreasing distance from the first tapered portion and is thicker with increasing distance from the first tapered portion.

Abstract: When implementing an origin reset, operating conditions for the origin reset are corrected in correspondence to changes in operating conditions such as the source voltage to implement an accurate origin reset.

Abstract: In the process steps a tentative value (m) of a deviation in a turning angle of a rotor of the stepping motor is determined each time the stepping motor runs. A cumulative amount of the tentative values (m) forms an estimated value (S) of the deviation in the turning angle of the rotor of the stepping motor. This estimated value (S) of the stepping motor. This estimated value (S) of the deviation is stored in a predetermined memory area. When an ignition switch is turned on, it is judged whether or not the estimated value (S) of the deviation thus stored until the ignition switch is turned on, exceeds a predetermined value. When it is judged that such estimated value (S) exceeds the predetermined value, an initial setting of the stepping motor is made.

Abstract: When a difference in opening angle of an air-mixing door between a target position and an actual position is larger in value than a width of an insensitive band area, a mixing door actuator is driven to a heating side or a cooling side depending on the amount of the difference so as to have the air-mixing door reach its target position in a condition in which the insensitive band area is eliminated. When the difference is smaller than the predetermined band width, i.e., when a drive position of the mixing door actuator is in the insensitive band width, this band width is effected so that the mixing door actuator is stopped in operation to stabilize the operation.

Abstract: A floating island with a water-purifying effect of the present invention has a floating body and an agent container. The floating body includes a planter made of a foamed resin, soil contained in the planter and plants planted in the soil. A plurality of openings are provided in the bottom of the planter through which water is supplied to the soil in the planter and roots of the plants grow into water. The agent container stores an oxygen-generating agent therein, which is attached on the outside of the bottom of the planter.