Contents

- 1 What is the difference between weight and bias?
- 2 Why do we need weights and bias in neural networks?
- 3 How do neural networks choose the weights and biases?
- 4 Why do we add bias in neural networks?
- 5 How many weights should a neural network have?
- 6 What are the number of weight and bias parameters?
- 7 How does parameter sharing reduce the training time?

## What is the difference between weight and bias?

Weights control the signal (or the strength of the connection) between two neurons. In other words, a weight decides how much influence the input will have on the output. Biases, which are constant, are an additional input into the next layer that will always have the value of 1.

### Why do we need weights and bias in neural networks?

In Neural network, some inputs are provided to an artificial neuron, and with each input a weight is associated. Weight increases the steepness of activation function. This means weight decide how fast the activation function will trigger whereas bias is used to delay the triggering of the activation function.

#### How do neural networks choose the weights and biases?

In the context of neural networks, it implies that the weights and biases that define the connection between neurons become more precise; this is, eventually, the weights and biases are selected such as the output from the network approximates the real value y(x) for all the training inputs.

**Why do you need a bias in neural network?**

Bias allows you to shift the activation function by adding a constant (i.e. the given bias) to the input. Bias in Neural Networks can be thought of as analogous to the role of a constant in a linear function, whereby the line is effectively transposed by the constant value.

**What happens if you initialize weights to zero?**

Initializing all the weights with zeros leads the neurons to learn the same features during training. Thus, both neurons will evolve symmetrically throughout training, effectively preventing different neurons from learning different things.

## Why do we add bias in neural networks?

### How many weights should a neural network have?

Each input is multiplied by the weight associated with the synapse connecting the input to the current neuron. If there are 3 inputs or neurons in the previous layer, each neuron in the current layer will have 3 distinct weights — one for each each synapse.

#### What are the number of weight and bias parameters?

Since the filter is of size 4, then from 4 x 5 matrix, we will get finally just one feature value. So, kernel_value (1 x 20) x weight_param (20 x 1) results in 1 feature value. Including 1 bias parameter, total parameters required is (20 + 1) = 21. So, total weight and bias parameters = 42 + 32 + 22 = 96.

**What are the weights and biases of a neural network?**

This article aims to provide an overview of what bias and weights are. The weights and bias are possibly the most important concept of a neural network. When the inputs are transmitted between neurons, the weights are applied to the inputs and passed into an activation function along with the bias.

**How to calculate trainable weights without weight sharing?**

We are going to derive the number of trainable weights without weight sharing and also with weight sharing, within the first convolutional layer of two popular CNN architectures: LeNet and AlexNet. (Input size width — filter size + (2*Padding) / stride )+ 1 = output width of convolutional layer 2.

## How does parameter sharing reduce the training time?

Parameter sharing reduces the training time; this is a direct advantage of the reduction of the number of weight updates that have to take place during backpropagation.