Abstract: A circular ring wave pool having an island in the center, the pool water depth becomes deeper the farther away from the island to the outside pool wall. A plurality of wave generators encompass the entire outer wall deep side of the pool. All wave generators point directly to the center of the island. Wave generators are synchronized in their action to produce waves that travel around the circular ring shaped pool in an endless loop therefore creating a traveling surfing wave that never ends. Many waves can be generated simultaneously creating a plurality of endless waves moving around the island. The sloping beach is at an angle to create a hollow tube breaking wave depending on wave speed and size. Hundreds of surfers can be in the pool at the same time all sitting out past the wave breakpoint waiting for an available wave to pass.

Abstract: An automobile exterior component, having good balance between impact resistance and fluidity and being excellent in coating heat resistance and rigidity, which is prepared by performing urethane coating or melamine coating on a molded article obtained by molding a resin composition which comprises a polyamide resin (A); a grafted polymer (B) prepared by graft polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer in the presence of a diene rubber; an unsaturated carboxylic acid-modified copolymer (C) which has a reduced viscosity of 0.2 to 0.5 dl/g and is prepared by polymerizing an unsaturated carboxylic acid monomer, an aromatic vinyl monomer and a vinyl cyanide monomer; a copolymer (D) prepared by polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer; and talc, wherein the amount ratio of (A), (B), (C) and (D) is in a specific range.

Abstract: In a high frequency power amplifier reduction of current consumption at the time of power down and an improvement in distortion of linearly modulated wave at the time of generation of its maximum output are automatically effected at the same time. Part of the high frequency output of a pre-stage amplifier is derived by a directional coupler inserted in the input part of a post-stage amplifier to be superposed through a DC voltage generator circuit on a gate bias voltage applied to the gate terminal of an FET in the post-stage amplifier, so that the gate bias voltage can be automatically controlled to its optimum value according to the output level required for the power amplifier.

Abstract: An optical head comprising a light source for emitting a light beam, an objective lens for focusing the light beam onto an optical record medium as a fine spot and a photodetector for receiving the light beam reflected by the optical record medium to derive an information signal, tracking error signal and focusing error signal. A Wollaston prism is arranged on an optical path along which both forward and return light beams propagate, so that the return light beam is separated from the forward light beam. The Wollaston prism is formed by cementing two wedge shaped-crystal plates having different directions of optic axes. The light source and photodetector may be arranged on a same substrate, and thus the optical head can be made small in size and less expensive in cost and can have a high reliability.