~/talk

Introduction to Neural Networks

Talkat PyCon UK 2018 · 2018-09-15..09-19· [machine-learning]
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Builds a working Python neural net implemented from scratch using sigmoid neurons, quadratic cost and stochastic gradient descent with backpropagation; trains on MNIST (40k train / 10k test) with a 784-30-10 architecture over ~30 epochs and reports 9,330/10,000 correct (~93% accuracy). Explains why sigmoids enable gradient-based learning, shows the backprop equations and pseudo-code, and contrasts the toy implementation with libraries like TensorFlow and Keras that reach ~98%.

AI-written summary · about

  1. 0:00Intro
  2. 1:31PERCEPTRON
  3. 4:06NETWORK LAYERS
  4. 5:11SIGMOID NEURON
  5. 5:50CLASSIFYING THE MNIST DATA SET
  6. 6:49MNIST NETWORK DESIGN
  7. 8:11TRAINING THE NETWORK
  8. 10:26LEARNING - MINIMISING COST USING
  9. 13:56NOTATION
  10. 14:54BACKPROPAGATION EQUATIONS
  11. 16:11BACKPROPAGATION PSEUDO
  12. 17:57STOCHASTIC GRADIENT DESCENT
  13. 22:48NN LIBRARIES FOR PYTHON
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