Deep learning is a subset of machine learning that uses artificial neural networks with multiple layers (deep neural networks) to progressively extract higher-level features from raw input. Here are the key components and concepts:
- Input Layer: Receives raw data and normalizes it for processing
- Hidden Layers: Multiple layers that transform data through weighted connections
- Output Layer: Produces the final prediction or output
- Activation Functions: Non-linear functions (ReLU, sigmoid, tanh) that help networks learn complex patterns
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Backpropagation
- Algorithm for calculating gradients in neural networks
- Efficiently updates weights by propagating error backwards through the network
- Uses chain rule to compute partial derivatives
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Gradient Descent Optimization
- Stochastic Gradient Descent (SGD)
- Mini-batch Gradient Descent
- Adaptive optimizers (Adam, RMSprop)
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Loss Functions
- Mean Squared Error (MSE) for regression
- Cross-Entropy Loss for classification
- Custom loss functions for specific tasks
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Regularization Techniques
- Dropout: Randomly deactivates neurons during training
- L1/L2 Regularization: Adds penalty terms to prevent overfitting
- Batch Normalization: Normalizes layer inputs for stable training
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Convolutional Neural Networks (CNNs)
- Specialized for processing grid-like data (images)
- Key components: Convolutional layers, pooling layers, fully connected layers
- Applications: Image classification, object detection, segmentation
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Recurrent Neural Networks (RNNs)
- Process sequential data with memory of previous inputs
- Variants: LSTM, GRU for handling long-term dependencies
- Applications: Time series prediction, natural language processing
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Transformers
- State-of-the-art architecture for sequence processing
- Self-attention mechanism for capturing relationships
- Applications: Language models, machine translation, text generation
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Autoencoders
- Unsupervised learning for dimensionality reduction
- Encoder-decoder architecture
- Applications: Feature learning, denoising, anomaly detection