Recurrent Neural Network

What are recurrent neural networks?

RNNs are a sort of neural network that is both powerful and robust, and they are one of the most promising algorithms in use because they are the only ones having an internal memory.

Recurrent neural networks, like many other deep learning techniques, are relatively new. They were first developed in the 1980s, but it wasn’t until recently that we realized their full potential.

RNNs have risen to prominence as a result of increased computer power, vast amounts of data we now have to deal with, and the advent of long short-term memory (LSTM) in the 1990s.

  • Recurrent artificial neural networks can recall critical details about the input they receive thanks to their internal memory, allowing them to anticipate what will happen next with great accuracy.

This is why they’re the chosen algorithm for text, speech, financial data, video, audio, and many other types of sequential data. In comparison to other algorithms, recurrent neural networks can acquire a far deeper grasp of a sequence and its context.

  • Recurrent neural networks in machine learning appear frequently in everyday life since they are utilized in the software that powers Siri and Google Translate.

How does it work?

You’ll need a working knowledge of “regular” feed-forward neural networks and sequential data to fully comprehend RNNs.

Sequential data is simply ordered data in which related items appear one after the other. Financial data or the DNA sequence are two examples.

Perhaps the most common sort of sequential data is time-series data, which is just a list of data points in chronological order.

  • The way RNNs and feed-forward neural networks channel information gives them their names.

The information in a feed-forward neural network only flows in one direction: from the input layer to the output layer, passing through the hidden layers. The data travels in a straight line through the network, never passing through the same node twice.

Feed-forward neural networks have no recollection of the information they receive and are poor predictors of what will happen next. A feed-forward network has no concept of time order because it only analyzes the current input. Except for its training, it has no recollection of what transpired in the past.

The information in recurrent neural network structure cycles via a loop. When it makes a judgment, it takes into account the current input as well as what it has learned from prior inputs.

  • Short-term memory is present in a typical RNN. They have a long-term memory when combined with an LSTM. However, because of its internal memory, a recurrent neural network may recall those characters. It generates output, copies it, and then feeds it back into the network.  recurrent neural networks combine information from the past with information from the present.

As a result, there are two inputs to an RNN: the present and the recent past. This is significant because the data sequence provides critical information about what will happen next, which is why an RNN can perform tasks that other algorithms cannot.

It’s worth noting that RNNs apply weights to both the current and prior inputs. In addition, a recurrent neural network will adjust the weights over time via gradient descent and backpropagation (BPTT).

RNNs may map one to many, many to many, and many to one, whereas feed-forward neural networks map one input to one output.

Different types of Recurrent Neural Network

  • BRNN is a type of RNN with a different network design. Bidirectional RNNs pull in future data to increase accuracy, whereas unidirectional only draws on previous inputs to create predictions.
  • GRUs (gated recurrent units): This RNN version is comparable to LSTMs in that it also aims to solve RNN models’ short-term memory problems. It uses hidden states instead of “cell states” to manage information, and instead of three gates, it only has two: a reset gate and an update gate. The reset and update gates, like the gates in LSTMs, determine how much and which information is retained.
  • Long short-term memory (LSTM) networks are a type of recurrent neural network that expands the memory capacity. As a result, it is highly suited to learning from significant experiences separated by lengthy periods of time.

The layers of an RNN, sometimes referred to as an LSTM network, are built using the units of an LSTM.

RNNs can recall inputs for a long time because of LSTMs. This is due to the fact that LSTMs store information in memory similar to that of a computer. The LSTM has the ability to read, write, and delete data from its memory.