Book Image

Deep Learning for Natural Language Processing

By : Karthiek Reddy Bokka, Shubhangi Hora, Tanuj Jain, Monicah Wambugu
Book Image

Deep Learning for Natural Language Processing

By: Karthiek Reddy Bokka, Shubhangi Hora, Tanuj Jain, Monicah Wambugu

Overview of this book

Applying deep learning approaches to various NLP tasks can take your computational algorithms to a completely new level in terms of speed and accuracy. Deep Learning for Natural Language Processing starts by highlighting the basic building blocks of the natural language processing domain. The book goes on to introduce the problems that you can solve using state-of-the-art neural network models. After this, delving into the various neural network architectures and their specific areas of application will help you to understand how to select the best model to suit your needs. As you advance through this deep learning book, you’ll study convolutional, recurrent, and recursive neural networks, in addition to covering long short-term memory networks (LSTM). Understanding these networks will help you to implement their models using Keras. In later chapters, you will be able to develop a trigger word detection application using NLP techniques such as attention model and beam search. By the end of this book, you will not only have sound knowledge of natural language processing, but also be able to select the best text preprocessing and neural network models to solve a number of NLP issues.
Table of Contents (11 chapters)

Output Gate and Current Activation

Note that all we have done is update the cell state until now. We need to generate the activation for the current state as well; that is, (h[t]). This is done using an output gate that is calculated as given:

Figure 7.20: Expression for output gate.

The input at timestep t is multiplied by a new set of weights, W_o, with the dimensions (n_h, n_x). The activation from the previous timestep (h[t-1]) is multiplied by another new set of weights, U_o, with the dimensions (n_h, n_h). Note that the multiplications are matrix multiplications. These two terms are then added and passed through a sigmoid function to squish the output, o[t], within a range of [0,1]. The output has the same number of dimensions as there are in cell state vector h (n_h, 1).

The output gate is responsible for regulating the amount by which the current cell state is allowed to affect the activation value for the timestep. In our example sentence, it is worth propagating the...