Abstract: A signal processor includes: a first adaptive filter that takes a first signal as input and generates a first pseudo signal; a first subtractor that subtracts the first pseudo signal from a second signal to supply a first differential signal as output; a second adaptive filter that takes the first signal as input to generate a second pseudo signal; a second subtractor that subtracts the second pseudo signal from the second signal to supply a second differential signal as output; a first step size control circuit that generates a first step size used in updating the first adaptive filter in accordance with the relation between the second pseudo signal and the second differential signal; and a second step size control circuit that generates a second step size used in updating the second adaptive filter in accordance with the relation between the first signal and the second signal.

Abstract: A robot includes first and second microphones and movable portions. The first microphone gathers a first sound reception signal by gathering mainly a target signal. The second microphone gathers a second reception sound signal by gathering mainly noise other than the target signal. The movable portions operate on the basis of the first sound reception signal output from the first microphone and the second sound reception signal output from the second microphone.

Abstract: A facial image identifying apparatus checks a facial image of a user captured by an image capturing unit such as a camera or the like against facial images of registered users for thereby identifying the user. When the facial image identifying apparatus starts to detect a facial image of an examinee user, it determines whether a situation of the image captured by the image capturing unit is appropriate to detect the facial image. If the situation is judged as being inappropriate, then information representing that the situation is inappropriate is presented to the examinee user. Based on the presented information, the examinee user can make an action to improve the situation of the captured image.

Abstract: An information delivery system and its method and a program of the system, in which plural robots are used and users can obtain information effectively via the plural robots from the wider range than the range where only one robot moves, are provided. Each of the plural robots provides an information delivering means to users and an information exchanging means with an information server. The plural robots and the information server connect to a network. The robot obtains information to be delivered to an identified person from the information storing in the information server. And the robot delivers the obtained information to the identified person.