# Introduction to Bayesian Deep Learning

## Introduction:

In this tutorial, we are learning about the introduction to Bayesian Deep Learning. The probability of neural networks can be examined by using a Bayesian interface. We can approximate this conceptual problem with simple modifications to standard neural network tools.

Bayes' theorem is a part of data science. It also includes the following disciplines: computer science, statistics, and probability. This theorem is used to calculate the probability of the event that is occurring based on the available significant data. Meanwhile, Bayes inference uses Bayes' theorem to change the probability of a hypothesis when faced with additional data.

Bayesian deep learning is an emerging field that combines uncertainty modelling of Bayesian methods with the presentation and representation of deep learning. Combining these two concepts provides a framework for solving many deep learning problems, like overfitting problems, weighted uncertainty problems, model comparisons, and many more.

Bayesian deep learning is sometimes referred to as a Bayesian neural network. This tutorial mainly teaches the basic introduction to Bayesian deep learning. We also learned the method, development, and many things which are related to this topic.

## What is meant by Bayesian Deep Learning?

Bayesian deep learning is shortly represented as BDL. It is dependent on deep learning theory and Bayesian probability theory. Meanwhile, Bayesian inference is important to statistics and probabilistic distribution machine learning. Probability is used mainly for model learning, uncertainty, and observable states. The main aim of Bayesian deep learning (BDL) is to provide an uncertainty estimate for deep learning.

Bayesian deep learning is an emerging field that combines uncertainty modelling of Bayesian methods with the presentation and representation of deep learning. Bayesian deep learning has always been fascinating and frightening. Uncertainty in neural networks is used to measure the accuracy of the prediction model. There are mainly two types of uncertainty in Bayesian modelling, which are discussed below -

### 1. Aleatoric uncertainty:

Aleatoric uncertainty is a part of uncertainty in the Bayesian modelling. It mainly used to measure the noise which is inherit in the time of observation. Example of it is sensor noise. The noise sensor can uniform in the data set. This uncertainty cannot be reduced even by collecting more data.

### 2. Epistemic uncertainty:

Epistemic uncertainty is another part of the uncertainty in the Bayesian modelling. This uncertainty is caused by the model itself, also known as model uncertainty. It captures our need for understanding about our collected data, which the model generated. By collecting more data, we can reduce this uncertainty.

So, the BDL models often estimate uncertainty by locating the distribution of sample weights or learning a direct probability map. Epistemic uncertainty is modelled by performing a preliminary distribution on the sample weights. It also can capture how much those weights vary with the data. On the other hand, arbitrary uncertainty is modelled by providing an output distribution, and it is also used to measure the noise of the given data set.

Many data scientists consider combining machine learning, Bayesian learning, and neural networks a successful application. However, the Bayesian neural networks are often very difficult to train. By using the backdrop method, we can easily train any neural network. We usually use Bayesian with Backprop for training BNN, which means Bayesian Neural Network.

## What is meant by Bayesian Inference and Marginalization?

The Bayesian interface is the learning process. It is used to find out the posterior distribution. This is the opposite of finding the best by optimizing the variance. On the other hand, to calculate the total final value, we need to marginalize the entire parameter space. But this is often impossible because we can have an infinite number of such data sets. Therefore, the Bayesian method used marginalization rather than an optimization technique.

Complex integration in the posterior leads to many variables for run parameter values. Bayesian interface often uses sampling methods such as Markov Chain Monte Carlo (MCMC) or differential equations instead of gradient descent. These strategies try to model after the use of simpler classification. VAEs are a new method for approximating complex distributions to normalize flows.

## What is the advantage of Bayesian Deep Learning?

Recently, many people have tried to combine the advantages of neural networks with the Bayesian methods. There are various advantages of Bayesian Deep Learning, which are discussed below -

1. Interpolation:

Interpolation is an important advantage of Bayesian Learning. Bayesian learning work includes pure architecture. When faced with a learning problem, a choice must be made between how much time and effort humans and computers should devote. When you build a designed machine, you create a model of the earth and find a good controller in that model.

The Bayesian method interpolates this extreme position because it may be a function of the Bayesian premise global model. This means that "thinking well" (referring to teaching patterns before the world) and "thinking hard" (as next) will be described. Many other machine learning methods still need this guarantee.

2. Intuition:

Intuition is another advantage of Bayesian Deep Learning. Bayesian learning involves two operations, which are prioritization and integration. These operations are often useful.

3. Language:

Language is another advantage of Bayesian Deep Learning. Bayesian and near Bayesian learning techniques have an associated language for the before and after expression. This is useful when dealing with "thinking hard" about a solution.

## What is the disadvantage of Bayesian Deep Learning?

Uncertainty estimation, especially for medical care, automobiles, etc., is important to the decision-making process. In Bayesian Deep Learning, there are various disadvantages, which are discussed below -

1. Computational infeasibility:

The Computational infeasibility is a disadvantage of the Bayesian Deep Learning (BDL). Suppose you can accurately predict every air molecule in the room. But, calculate the posterior can take a lot of time. This difficulty means that there is a need to make computational predictions.

2. Theoretical infeasibility:

The theoretical infeasibility is another disadvantage of Bayesian Deep Learning. It turned out to take a lot of work to prior specifications. Here, we need to specify the real number for each setting of the model parameters. Many people knowledgeable in Bayesian learning do not see this difficulty for some reasons, which are given below -

1. They know the language that allows prior specification. Obtaining this information requires great effort.
2. They are lying. Their actual prior is not specified earlier.

3. Unautomated:

Unautomated is another disadvantage of Bayesian Deep Learning. "Critical thinking" is a part of Bayesian research in the "Bayes employment" rule. As new learning problems arise, Bayesian assures that engineers must solve them.

## What is the future development of the BDL (Bayesian Deep Learning)?

The future development of the BDL (Bayesian Deep Learning) is learned here. The Bayesian Deep Learning theorem is used to calculate the probability of the event that is occurring based on the available significant data. It is dependent on deep learning theory and Bayesian probability theory.

Here, we mainly learn about the future development of the BDL. The main barriers to the widespread use of Bayesian Deep Learning (BDL) in the past have been computational efficiency. The absence of publicly available software packages. Recent initiatives have taken a solid step towards these issues.

For example, significant work has been done on hardware and software to speed things up, and new software packages such as Edward have been developed specifically for design and theory.

In the future, we expect BNNs to progress in small data, batch learning, and model compression. More broadly, further research will be conducted based on the general scope of BDL. Bayesian deep learning uses its ability to reproduce the image structure in various tuning problems. The example of it is computer vision and natural language processing.

## Conclusion:

In this tutorial, we are learning about the introduction to Bayesian Deep Learning. Bayesian deep learning is an emerging field that combines uncertainty modelling of Bayesian methods with the presentation and representation of deep learning. Bayesian deep learning has always been fascinating and frightening. That may also be disappointing, as it is based on much speculation about what is happening.

It can also learn from small datasets and then inform us about the uncertainty of our predictions. Here, we also discuss the advantages and disadvantages of Bayesian Deep Learning. If the problem is to be solved, Bayesians should work on it and have a good chance of solving it.

In summary, Bayesian deep learning can provide a framework for integrating uncertainty into the prediction of deep neural networks.