Abstract: An active noise control system selects one reference sensor providing a reference signal with the largest coherence to a noise signal, among a plurality of available reference sensors, as a first entry of a reference sensor set. After selecting the first entry, the active noise control system repeats a process in which a sensor capable of providing the largest information quantity to a current reference sensor set among remaining sensors is selected as a new entry of a reference sensor set, until a desired number of sensors is reached or a desired control level is reached. When the reference sensor set is determined, the active noise control system utilizes the entries of the reference sensor set to generates a noise control signal suitable for canceling the noise signal.

Abstract: The present invention relates to a method for predicting physical properties of an amorphous porous material which may predict an acoustic physical property value and an absorption coefficient from parameters of an amorphous porous material, and may estimate the acoustic characteristics with the amorphous porous material which is an amorphous specimen even without separately producing a formalized specimen such as a cylindrical specimen or a flat specimen. Further, the method for predicting physical properties of the amorphous porous material may estimate the acoustic physical properties through the analysis of a three-dimensional pore connection structure, which is a microstructure of an amorphous specimen, even without acoustic impedance, thereby estimating the acoustic physical properties which accurately reflect the characteristics of the actual specimen.

Abstract: An active noise control system selects one reference sensor providing a reference signal with the largest coherence to a noise signal, among a plurality of available reference sensors, as a first entry of a reference sensor set. After selecting the first entry, the active noise control system repeats a process in which a sensor capable of providing the largest information quantity to a current reference sensor set among remaining sensors is selected as a new entry of a reference sensor set, until a desired number of sensors is reached or a desired control level is reached. When the reference sensor set is determined, the active noise control system utilizes the entries of the reference sensor set to generates a noise control signal suitable for canceling the noise signal.

Abstract: The present invention relates to a method for predicting physical properties of an amorphous porous material which may predict an acoustic physical property value and an absorption coefficient from parameters of an amorphous porous material, and may estimate the acoustic characteristics with the amorphous porous material which is an amorphous specimen even without separately producing a formalized specimen such as a cylindrical specimen or a flat specimen. Further, the method for predicting physical properties of the amorphous porous material may estimate the acoustic physical properties through the analysis of a three-dimensional pore connection structure, which is a microstructure of an amorphous specimen, even without acoustic impedance, thereby estimating the acoustic physical properties which accurately reflect the characteristics of the actual specimen.

Abstract: Disclosed is a method of manufacturing soundproofing composite, and a soundproofing composite manufactured by the aforementioned method, the method comprising preparing a mixture by dissolving PP resin and nanoclay in a solvent; and volatilizing the solvent from the mixture. According to the present invention, the composite is manufactured by dissolving PP resin and nanoclay, to thereby realize great stiffness and soundproofing properties.

Abstract: Disclosed is a method of manufacturing soundproofing composite, and a soundproofing composite manufactured by the aforementioned method, the method comprising preparing a mixture by dissolving PP resin and nanoclay in a solvent; and volatilizing the solvent from the mixture. According to the present invention, the composite is manufactured by dissolving PP resin and nanoclay, to thereby realize great stiffness and soundproofing properties.

Abstract: The present disclosure relates to a method of beat tuning in a slightly asymmetric ring-type structure, and can be effectively used to control the beat property of a structure such as a bell, which can be modeled to a slightly asymmetric ring. A method of beat tuning in a slightly asymmetric ring structure includes the steps of establishing an original ring model which simplifies said ring structure, establishing an equivalent imperfection mass model which is equivalent to said original ring model and has at least one or more point masses on an asymmetric ring, determining magnitudes and positions of the point masses in said equivalent imperfection mass model based on mode data of said original ring model, and determining magnitudes and positions of masses which should be added to or removed from said equivalent imperfection mass model in order to obtain desired beat properties.

Abstract: An optimal shape of a poroelastic acoustical foam which can maximize sound-absorbing effect is disclosed. The poroelastic acoustical foam is made of a wedge-shaped wedge unit where the cross section is reduced in one direction, and a bowl-shaped bowl unit where formed at one end of the wedge unit where the cross section of the wedge unit is small, and the other end, where the cross section of the wedge unit is large, is separated from the wall, forming an air layer.