Federated learning system, federated learning method, and recording medium storing instructions to perform federated learning method

A non-transitory computer-readable recording medium storing a computer program, comprising commands for a processor to perform a federated learning method, the method comprising:

• preparing a local learning model configured to perform federated learning with a central server including a central learning model and other client device,
• updating status information of the central learning model to an extraction unit of the local learning model,
• training the local learning model by using individual training data, and
• transmitting the status information of the trained local learning model stored in the extraction unit of the trained local learning model to the central server to be updated in an extraction unit of the central learning model,
• wherein the training the local learning model includes normalizing a feature vector of training data input to the local learning model.

A federated learning method performed by a central server and a plurality of client devices, comprising:

• transmitting, by the central server, status information of a central learning model to each client device;
• updating, by each client device, the status information of the central learning model to a local learning model;
• training, by each client device, the local learning model by using individual training data;
• transmitting, by each client device, status information of the trained local learning model to the central server;
• and
• updating, by the central server, the central learning model by using the status information of the trained local learning model received from each client device,
• wherein the training the local learning model includes normalizing a feature vector of training data that is input to the local learning model, and
• wherein the updating the central learning model includes normalizing a feature vector of training data that is input to the central learning model.