Coursera Machine Learning : W5 Neural Network

W5 Backward Propagation

Notes

Cost Function and Backpropagation

• total layer number: L, nodes # in layer l: s_l, k # of units in output layer
• cost function
• Backpropagation
• Random initialization: symmetry breaking
• Arch: Reasonable default: 1 hidden layer; multiple layers: same # of nodes in each layer; more layers, better performance

• backward propagation

• cyan /saian/ 青色
• magenta 品红