Abstract: Disclosed is a localization method of a source of unknown signal based on a TDOA method, comprising a data obtaining step S100 of receiving and obtaining the unknown signal using multiple sensors; an objective function value calculating step S200 of finding a cross-correlation value, and calculating an objective function value; a reference sensor selecting step S300 of selecting a reference sensor for calculating a TDOA measurement value; a TDOA measurement value calculating step S400 of finding a time when a cross-correlation value Rri(?) found by performing cross-correlation of signal received in each of the reference sensor selected and an i-th sensor with respect to a delay time ? becomes maximum; and a location estimating step S500 of localizing the source of unknown signal. Therefore, the present invention can precisely localize the source of the unknown signal.

Abstract: Provided is a flow control valve including a valve body including a flow path, a first poppet fixed in the valve body including an inlet through which a fluid flows in, and an outflow hole through which the fluid flows out to the flow path of the valve body, a second poppet fixed in the valve body including an outlet through which the fluid flows out, and an inflow hole through which the fluid flows in from the flow path of the valve body, a sleeve to adjust an area of the outflow hole, a spool formed to slide along an external surface of the second poppet, and bellows of which one end is coupled with the first poppet and the other end is coupled with the spool.