Abstract: A work assistance system includes a storage storing work data for each of a plurality of devices, the work data indicating work performed to maintain the plurality of devices, a setter configured to set at least one attribute among a plurality of prescribed attributes with respect to the work data stored in the storage, an extractor configured to interpret the attribute set in the work data and to extract work data in which a specific attribute is set, and a provider configured to provide the work data extracted by the extractor.

Abstract: A work assistance system includes a storage storing work data for each of a plurality of devices, the work data indicating work performed to maintain the plurality of devices, a setter configured to set at least one attribute among a plurality of prescribed attributes with respect to the work data stored in the storage, an extractor configured to interpret the attribute set in the work data and to extract work data in which a specific attribute is set, and a provider configured to provide the work data extracted by the extractor.

Abstract: With the circuit construction of a heterodyne receiver, a control circuit for correcting the amplitude level of a local oscillation signal according to an output signal of a detector circuit is connected to the output terminal of an amplifier for amplifying the local oscillation signal to set the amplitude level of the local oscillation signal input to the mixer to an adequate level.

Abstract: A heterodyne receiver of the present invention is of a heterodyne system including a voltage controlled circuit and a phase locked loop circuit. The receiver further includes a tuned voltage signal compensating circuit adapted to deliver a frequency passband compensating signal to a bandpass filter on the basis of a variation of an output signal obtained as a result of comparison made between a tuned voltage signal from the phase locked loop circuit and a detected signal from a detector. The heterodyne circuit can obtain a stable nearby frequency selectivity characteristic even in the case where there arises a temperature variation in the receiver.