1. Neural Network Architecture

The basic structure and components of neural networks. Key points include:

  • Layers: Neural networks are composed of layers—input, hidden, and output layers. Each layer consists of nodes (neurons) connected by edges (weights).
  • Activation Functions: Functions like sigmoid, tanh, and ReLU that introduce non-linearity into the network.
  • Feedforward Networks: The basic type of neural network where connections between nodes do not form cycles.
  • Backpropagation: The algorithm used to train neural networks by adjusting weights through gradient descent to minimize error.

2. Neural Network Training

How neural networks learn from data:

  • Training Data: The process starts with a dataset split into training and validation sets.
  • Loss Functions: Functions like mean squared error or cross-entropy used to quantify the difference between the predicted and actual output.
  • Gradient Descent: An optimization algorithm used to minimize the loss function by updating weights.
  • Epochs and Batches: Training involves multiple epochs, where an epoch is a complete pass through the training data. Data may be divided into batches to update weights incrementally.
  • Overfitting and Regularization: Techniques like dropout, L2 regularization, and early stopping used to prevent the model from overfitting the training data.

3. Applications of Neural Networks

Various practical applications of neural networks in the web context:

  • Recommendation Systems: Neural networks can predict user preferences and suggest items based on user behavior and history.
  • Natural Language Processing (NLP): Applications include sentiment analysis, chatbots, and machine translation.
  • Image Recognition: Neural networks are used for tasks like image classification and object detection.
  • Time Series Prediction: Applications in forecasting stock prices, weather, and user engagement metrics.