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What is a Perceptron or an Artificial Neuron ? (Neural Network, Machine Learning, Deep Learning)



Artificial neural network is derived from biology; we try to mimic biological neuron with an artificial neuron termed perceptron.

Biological Neuron

                                                                  Artificial Neuron

The clear definition of it can be found here: https://biologydictionary.net

Dendrites are projections of a neuron (nerve cell) that receive signals (information) from other neurons. The transfer of information from one neuron to another is achieved through chemical signals and electric impulses, that is, electrochemical signals. The information transfer is usually received at the dendrites through chemical signals, then it travels to the cell body (soma), continues along the neuronal axon as electric impulses, and it is finally transferred onto the next neuron at the synapse, which is the place where the two neurons exchange information through chemical signals. At the synapse meet the end of one neuron and the beginning—the dendrites—of the other.

Now we can look at how the artificial neuron works, we assume that the input to the neuron as any real world signal with a numerical value such as 12 and 4 as shown below. To begin, usually, the weights usually will be assigned randomly (here 0.5 and -1)


The next step involves multiplying the inputs with the weights and then summed up together. Then the activation function output some states such as ‘1’ or ‘0’, based on the summation. For example if the summation is above 0 it outputs ‘1’ and vice versa.


In case if both inputs are ‘0’ then whatsoever be the weights we always get ‘0’ as output, hence a Bias term is added.




The mathematical representation for the ‘n’ input system (and a bias) is provided as below


The upgradation of perceptron is multiple perceptron network, which has more layers then single perceptron
And if the number of hidden layer is greater than 3, then its termed as deep network/learning.



Comments

  1. ekeeda001October 16, 2019 at 10:14 PM

    Thank you for sharing best Engineering subject knowledge Its very valuable and supportive for student.
    get more: Image Processing

    ReplyDelete

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