⇦ Back to Convolutional Neural Networks (CNNs)

Introduction

Deep learning is a subset of machine learning that involves training artificial neural networks to learn from data. It has revolutionized the field of artificial intelligence and has led to breakthroughs in areas such as computer vision, natural language processing, and speech recognition. In this lesson, we will focus on the basics of deep learning and how it works.

Artificial Neural Networks

Artificial neural networks are the building blocks of deep learning. They are composed of layers of interconnected nodes that process information. The input layer receives data, and the output layer produces a prediction. The layers in between are called hidden layers, and they extract features from the input data. The weights and biases of the nodes are adjusted during training to minimize the error between the predicted output and the actual output.

Training Deep Neural Networks

Training a deep neural network involves feeding it a large amount of labeled data and adjusting the weights and biases of the nodes to minimize the error between the predicted output and the actual output. This is done using an optimization algorithm such as gradient descent. The loss function measures the error between the predicted output and the actual output, and the backpropagation algorithm calculates the gradient of the loss function with respect to the weights and biases of the nodes.

Optimization Algorithms

There are several optimization algorithms that can be used to train deep neural networks. One popular algorithm is Adam, which combines the advantages of two other algorithms, AdaGrad and RMSprop. Adam is efficient and requires little memory, making it suitable for large datasets. Another popular algorithm is RMSprop, which adjusts the learning rate based on the average of the squared gradients. This helps prevent the learning rate from becoming too large or too small.

Challenges in Deep Learning

Despite its many successes, deep learning still faces several challenges. One challenge is overfitting, which occurs when a model is too complex and fits the training data too closely, resulting in poor performance on new data. Regularization techniques such as dropout and weight decay can help prevent overfitting. Another challenge is the need for large amounts of labeled data, which can be expensive and time-consuming to obtain. Transfer learning and data augmentation are two techniques that can help address this challenge.

Conclusion

Deep learning has revolutionized the field of artificial intelligence and has led to breakthroughs in many areas. Artificial neural networks are the building blocks of deep learning, and training them involves adjusting the weights and biases of the nodes using an optimization algorithm. There are several optimization algorithms available, including Adam and RMSprop. Despite its many successes, deep learning still faces several challenges, including overfitting and the need for large amounts of labeled data.

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⇦ 4.3 Preprocessing and Data Augmentation 4.5 Transfer Learning and Fine-Tuning ⇨