Abstract: An objective of the present disclosure is to allow a situation in a conversation of a user to be recognized as a context and allow an item appropriate for the situation to be presented. An information recommendation device according to the present disclosure includes a context extraction module 24 that extracts, from the conversation of the user, a keyword representing a topic, a similarity determination module 31 that refers to a knowledge base 13 storing recommended items linked to communication contexts each including the keyword to extract the recommended items and the communication contexts that are linked to the extracted keyword and selects, from among the extracted communication contexts, the communication context similar to the topic, and an information search module 32 that acquires, from the knowledge base 13, the recommended item linked to the selected communication context.

Abstract: An object of the present disclosure is to recognize a situation during a user's conversation as a context and make it possible to present items suitable for the situation. An information recommendation apparatus 100 according to the present disclosure includes a context extraction module 24 which extracts keywords which are in a topic from a user's conversation, a similarity determination module 31 which refers to a knowledge base 13 storing recommended items associated with communication contexts including keywords, extracts recommended items and communication contexts associated with the extracted keywords, and selects communication contexts similar to the topic among the extracted communication contexts, and an information search module 32 which acquires from the knowledge base 13 recommended items associated with the selected communication contexts.

Abstract: It is the object of the present invention to provide a transmission system that transmits a control signal corresponding to the overhead accommodating time division multiplexing information at a frequency that is the same (or nearly the same) as that of the main signal. In order to attain this object, an optical transmitter broadens in a time range the optical waveform of the OTDM signal having a wavelength &lgr;0 and the control light having a wavelength &lgr;1(≈&lgr;0), and multiplexes the signal light having an optical peak intensity set low compared to the OTDM signal peak intensity and sending this to an optical transmission fiber.

Abstract: It is an object of the present invention to provide an optical clock phase lock loop capable of a higher operational speed than the conventional technology by utilizing high-speed optical phenomena other than gain modulation. In an optical clock phase lock loop for conducting locking control by means of obtaining the correlation of an optical signal and optical clock, after combining an optical clock of a short pulse containing a harmonics component with an optical signal by means of an optical coupler 102, and providing the resultant light to traveling-wave semiconductor laser amplifier 103, the correlation signal of the optical signal and optical clock included in the output signal of this traveling-wave semiconductor laser amplifier 103 is detected by means of optical bandpass filter 104.

Abstract: It is an object of the present invention to provide an optical clock phase lock loop capable of a higher operational speed than the conventional technology by utilizing high-speed optical phenomena other than gain modulation. In an optical clock phase lock loop for conducting locking control by obtaining the correlation of an optical signal and optical clock, after combining an optical clock of a short pulse containing a harmonics component with an optical signal by using an optical coupler 102, and providing the resultant light to traveling-wave semiconductor laser amplifier 103, the correlation signal of the optical signal and optical clock included in the output signal of this traveling-wave semiconductor laser amplifier 103 is detected by an optical bandpass filter 104.