Disclosed herein is a separate learning system and method using a
two-layered neural network having target values for hidden nodes. The
separate learning system of the present invention includes an input layer
for receiving training data from a user, and including at least one input
node. A hidden layer includes at least one hidden node. A first
connection weight unit connects the input layer to the hidden layer, and
changes a weight between the input node and the hidden node. An output
layer outputs training data that has been completely learned. The second
connection weight unit connects the hidden layer to the output layer,
changing a weight between the output and the hidden node, and calculates
a target value for the hidden node, based on a current error for the
output node. A control unit stops learning, fixes the second connection
weight unit, turns a learning direction to the first connection weight
unit, and causes learning to be repeatedly performed between the input
node and the hidden node if a learning speed decreases or a cost function
increases due to local minima or plateaus when the first connection
weight unit is fixed and learning is performed using only the second
connection weight unit, thus allowing learning to be repeatedly performed
until learning converges to the target value for the hidden node.