The noise suppression method of individual active noise reduction system comprises the steps that: (1) initial noise digital signals are received and converted to serve as input signals of a BP neural network; (2) the input signals are processed to generate secondary digital signals; (3) the secondary digital signals are output to a loudspeaker and secondary noise is generated; (4) remained noise digital signals obtained by overlapping the initial noise and the secondary noise are received; whether remained noise digital signals is continuously constant for the set times is judged; if yes, the secondary digital signals are kept outputting; (5) if not, BP neural network parameters are optimized and adjusted with the amplitude of the remained noise digital signals being minimum as the optimality principle; remained noise digital signals of previous step are served as new input signals and the step (2) is executed again.

The noise suppression method of individual active noise reduction system comprises the steps that: (1) initial noise digital signals are received and converted to serve as input signals of a BP neural network; (2) the input signals are processed to generate secondary digital signals; (3) the secondary digital signals are output to a loudspeaker and secondary noise is generated; (4) remained noise digital signals obtained by overlapping the initial noise and the secondary noise are received; whether remained noise digital signals is continuously constant for the set times is judged; if yes, the secondary digital signals are kept outputting; (5) if not, BP neural network parameters are optimized and adjusted with the amplitude of the remained noise digital signals being minimum as the optimality principle; remained noise digital signals of previous step are served as new input signals and the step (2) is executed again.

A vibration reduction unit and a transformer comprising same are disclosed. The vibration reduction unit according to one aspect of the present disclosure may comprise: a first frame forming one portion of the exterior thereof; a second frame which forms the other portion of the exterior thereof, and which is coupled to the first frame; a resonance space formed inside the second frame so as to reduce transmitted vibration or noise by means of resonance; and a pipe member penetratively coupled to the first frame such that the resonance space communicates with the outside.

A vibration reduction unit and a transformer comprising same are disclosed. A vibration reduction unit according to one aspect of the present invention comprises: a rod part connected to the outside and extending in one direction; and a mass part coupled to the rod part so as to reduce vibration transmitted to the rod part, wherein the mass part may comprise: a mass member formed to have a predetermined mass; and a mass hollow formed to penetrate the inside of the mass member and to which the rod part is coupled.