Abstract: A signal filtering device includes: a separation unit that separates a predetermined number of possibility signals from a mixed signal as possibilities of a target signal; an encoding unit that encodes related information of the target signal into a first feature vector and encodes the predetermined number of possibility signals into the predetermined number of second feature vectors; and a selection unit that derives a similarity between the first feature vector and the second feature vector for each of the possibility signals, and selects a possibility signal of the possibility signals having the highest similarity as the target signal from the predetermined number of possibility signals. The selection unit may derive an inner product of the first feature vector and the second feature vector as the similarity. The predetermined number of possibility signals may be voice signals associated with the predetermined number of sound sources.

Abstract: An X.25 protocol apparatus can communicate with another X.25 apparatus or a X.32 apparatus through a telephone network, an ISDN network, or a PBX network, by attaching protocol conversion system to the X.25 apparatus. The conversion system has a pair of signal identification portions (1, 6) for separating a receive packet to a data packet and a control packet, a call process portion (3, 12) for dial signal process, and an address table (4) and a packet edition portion (5) for address conversion of a control packet. A data packet is forwarded from one signal identification portion to another signal identification portion through direct path (53). A control packet is forwarded to a control packet identification portion (2) for control process which includes dial signal process, address conversion, and protocol sequences. This system is applicable to couple a data communication network which has a X.32 correspondence portion to another data communication network.