Abstract: In order to facilitate fixed-point monitoring over a wide area and for a long time, this water area monitoring device comprises: a detection unit for information, such as water area intrusion, which detects, from sound data that is acquired by means of optical fibers installed in the water or the water bottom and is data pertaining to a sound or a vibration at the respective positions of the optical fibers, at least any one among sounds of water area intrusion or the like that indicate intrusion into a target water area or water area intrusion or the like, which is a prescribed behavior in the target water area, at a time at which sound data is acquired, and changes in sounds or vibrations not caused by the water area intrusion or the like; and an output unit which outputs information indicating the sound such as water area intrusion.

Abstract: A decoding device includes a memory and a processor configured to execute inputting a code word encoded by a polar code from an original message; decoding the original message from the code word based on a conditional probability expressed by a symmetric parameterization and having observation information as a condition; and outputting the decoded original message.

Abstract: A decoding device includes a memory and a processor configured to execute inputting a code word encoded by a polar code from an original message; decoding the original message from the code word based on a conditional probability expressed by a symmetric parameterization and having observation information as a condition; and outputting the decoded original message.

Abstract: In order to facilitate fixed-point monitoring over a wide area and for a long time, this water area monitoring device comprises: a detection unit for information, such as water area intrusion, which detects, from sound data that is acquired by means of optical fibers installed in the water or the water bottom and is data pertaining to a sound or a vibration at the respective positions of the optical fibers, at least any one among sounds of water area intrusion or the like that indicate intrusion into a target water area or water area intrusion or the like, which is a prescribed behavior in the target water area, at a time at which sound data is acquired, and changes in sounds or vibrations not caused by the water area intrusion or the like; and an output unit which outputs information indicating the sound such as water area intrusion.

Abstract: An acoustic sensor that uses an optical fiber and has a high directivity is provided. An acoustic sensor includes a sensing part and an interrogator. The sensing part has a sensing element composed of an optical fiber. The interrogator is connected to the sensing part, sends a pulse light P to the sensing part, and detects an acoustic wave sensed by the sensing part based on a reflected return light from the sensing part. The sensing element is composed of the optical fiber folded in such a way that it reciprocates a plurality of number of times along a directivity direction in which directional sensitivity is exhibited.

Abstract: A submarine power feeding branching device comprises a constant current-constant current converter which isolates an input side for a trunk submarine cable from an output side for a branch submarine cable. The converter receives a first constant current and produces a second constant current by using the first constant current. The second constant current is supplied to the output side while the first constant current is returned to the input side. Because the input side and the output side are isolated, it is easy to add/remove the device to/from a submarine power feeding system. Intensity of the second constant current can be controlled by controlling duty ratios of switches included in the converter. Thus, it is possible that the intensity of the second constant current is equal to that of the first constant current. Therefore, a submarine repeater can be provided along either the trunk cable or the branch cable.

Abstract: A submarine power feeding branching device comprises a constant current-constant current converter which isolates an input side for a trunk submarine cable from an output side for a branch submarine cable. The converter receives a first constant current and produces a second constant current by using the first constant current. The second constant current is supplied to the output side while the first constant current is returned to the input side. Because the input side and the output side are isolated, it is easy to add/remove the device to/from a submarine power feeding system. Intensity of the second constant current can be controlled by controlling duty ratios of switches included in the converter. Thus, it is possible that the intensity of the second constant current is equal to that of the first constant current. Therefore, a submarine repeater can be provided along either the trunk cable or the branch cable.

Abstract: A submarine power feeding branching device comprises a constant current-constant current converter which isolates an input side for a trunk submarine cable from an output side for a branch submarine cable. The converter receives a first constant current and produces a second constant current by using the first constant current. The second constant current is supplied to the output side while the first constant current is returned to the input side. Because the input side and the output side are isolated, it is easy to add/remove the device to/from a submarine power feeding system. Intensity of the second constant current can be controlled by controlling duty ratios of switches included in the converter. Thus, it is possible that the intensity of the second constant current is equal to that of the first constant current. Therefore, a submarine repeater can be provided along either the trunk cable or the branch cable.

Abstract: A submarine cable power feeding system includes N (N is an integer of 2 or larger) main submarine cables extending from the land in the offshore direction, N-stage (N is an integer of 2 or larger) submarine feed branching devices, and first to Nth (N is an integer of 2 or larger) sub submarine cables. Each submarine feed branching device is connected to the main submarine cable to receive constant-voltage power from a constant-voltage feed unit. Each sub submarine cable connects the Nth-stage submarine feed branching device, connected to the Nth main submarine cable, to the adjacent submarine feed branching device through submarine repeaters, thereby receiving power from a constant-current feed unit. Each constant-current feed unit is built in the submarine feed branching device. The submarine feed branching devices and the submarine repeaters are arranged in a matrix on a plane.

Abstract: A submarine power feeding branching device comprises a constant current-constant current converter which isolates an input side for a trunk submarine cable from an output side for a branch submarine cable. The converter receives a first constant current and produces a second constant current by using the first constant current. The second constant current is supplied to the output side while the first constant current is returned to the input side. Because the input side and the output side are isolated, it is easy to add/remove the device to/from a submarine power feeding system. Intensity of the second constant current can be controlled by controlling duty ratios of switches included in the converter. Thus, it is possible that the intensity of the second constant current is equal to that of the first constant current. Therefore, a submarine repeater can be provided along either the trunk cable or the branch cable.

Abstract: A submarine cable power feeding system includes N (N is an integer of 2 or larger) main submarine cables extending from the land in the offshore direction, N-stage (N is an integer of 2 or larger) submarine feed branching devices, and first to Nth (N is an integer of 2 or larger) sub submarine cables. Each submarine feed branching device is connected to the main submarine cable to receive constant-voltage power from a constant-voltage feed unit. Each sub submarine cable connects the Nth-stage submarine feed branching device, connected to the Nth main submarine cable, to the adjacent submarine feed branching device through submarine repeaters, thereby receiving power from a constant-current feed unit. Each constant-current feed unit is built in the submarine feed branching device. The submarine feed branching devices and the submarine repeaters are arranged in a matrix on a plane.

Abstract: A robbery-proof mechanism for a vehicle mounted electronic apparatus wherein a cover for covering the electronic apparatus is accommodated in the upper space of the electronic apparatus and can be driven by a small scale drive mechanism without moving the electronic apparatus.