Introduction: Neural Networks in Machine Learning

We used neural networks for some classical needs in understanding customer data.  Now they have expanded in use, via advanced hardware, to provide much 'deeper' results.   Here an introduction, quite technical beyond the first few pages. Has some Python code implementation of the underlying concepts. Worth examining for practitioners.

Artificial Neurons and Single-Layer Neural Networks
- How Machine Learning Algorithms Work Part 1
-- written by Sebastian Raschka on March 14, 2015
  
This article offers a brief glimpse of the history and basic concepts of machine learning. We will take a look at the first algorithmically described neural network and the gradient descent algorithm in context of adaptive linear neurons, which will not only introduce the principles of machine learning but also serve as the basis for modern multilayer neural networks in future articles.... "