Abstract: An optical coupling structure includes a light source that emits light; and an optical waveguide that has on a given end, a mirror surface that reflects the light emitted from the light source, the optical waveguide guiding the light reflected by the mirror surface to another end. In the optical coupling structure, a traveling direction of the light emitted from the light source is inclined toward the given end of the optical waveguide and is, with respect to a normal line of the mirror surface, at an angle that is greater than 45 degrees and that satisfies a condition for complete reflection of light on the mirror surface and a condition for complete reflection of light in the optical waveguide.

Abstract: When a first server node fails in a cluster system, a client node device transmits failure detection information to a second server node device. Upon receipt of the failure detection information, the second server node device transmits a survival confirmation request to the first server node device. When receiving no survival confirmation response from the first server node device, the second server node device determines that the first server node device has failed and starts the switching control of a server node device which performs a service process. Upon receipt of failure detection information, the second server node device starts switching control when further receiving failure detection information from another client node device.

Abstract: A second printed wiring board is opposed to a surface of the first printed wiring board. A support member supports the first and second printed wiring boards. A first connector is mounted on the first printed wiring board. A second connector is mounted on the second printed wiring board. A wiring connects the first printed wiring board to the second printed wiring board. The first and second connectors are separately mounted on the first and second printed wiring boards, respectively. The sizes of the first and second printed wiring boards can be reduced as compared with the case where connectors are arranged in a row on a single printed wiring board, for example. This results in a reduction in the size of the printed circuit board unit. A large number of the printed circuit board units can be coupled to the back panel.

Abstract: The present invention provides a magnetic recording medium with a reduced tendency for a free layer to become thicker near an outer periphery than near an inner periphery of a recording zone as well as provides an information reproducing apparatus which is equipped with the magnetic recording medium and reproduces information according to the magnetization at various points on the magnetic recording medium. A magnetic layer carries information in an outer zone outside a predetermined inner zone around a through-hole. That part of the free layer which is located in the outer zone is thinner near the outer periphery than near the inner periphery.

Abstract: An information recording medium wherein the key information is recorded by arrangement of a unit area recorded irreversibly and a unit area not recorded irreversibly to effect the truth judgment of the medium in accordance with the result of whether or not the reproduction of the key information can be effected, the information recording medium where the illegal usage of the medium is adapted to be prevented without inputting the information on to the medium truth judgment into the processing apparatus by provision of the medium firm information, a reproducing method for the same, a truth judging method for the same, and a recording/reproducing apparatus for the same.