  We introduce techniques for rapidly transferring the information stored in
one neural net into another neural net. The main purpose is to accelerate the
training of a significantly larger neural net. During real-world workflows, one
often trains very many different neural networks during the experimentation and
design process. This is a wasteful process in which each new model is trained
from scratch. Our Net2Net technique accelerates the experimentation process by
instantaneously transferring the knowledge from a previous network to each new
deeper or wider network. Our techniques are based on the concept of
function-preserving transformations between neural network specifications. This
differs from previous approaches to pre-training that altered the function
represented by a neural net when adding layers to it. Using our knowledge
transfer mechanism to add depth to Inception modules, we demonstrate a new
state of the art accuracy rating on the ImageNet dataset.
