Neural Networks and Fuzzy Systems

The Basic Neuron

Rizoan Toufiq

Assistant Professor

Department of Computer Science & Engineering

Rajshahi University of Engineering & Technology

Modeling the single neuron

• We can summarizes them as follows:
• The output from a neuron is either on or off.
• The output depends only on the inputs. A certain number must be on at any one time in order to make the neuron fire.

Modeling the single neuron

Modeling the single neuron

Modeling the single neuron

Modeling the single neuron

Modeling the single neuron

Learning in simple neuron

Learning in simple neuron

Our learning paradigm can be summarized as follows:

• set the weights and thresholds randomly
• present an input
• calculate the actual output by taking the thresholded value of the weighted sum of the inputs
• alter the weights to reinforce correct decisions and discourage incorrect decisions-i.e. reduce the error
• present the next input etc �

The perceptron learning algorithm

The perceptron learning algorithm

The perceptron learning algorithm

The perceptron learning algorithm

The Perceptron: A Vectorial Perspective

The Perceptron: A Vectorial Perspective

The Perceptron: A Vectorial Perspective

The Perceptron Learning Rule: Proof

The Perceptron Learning Rule: Proof

The Perceptron Learning Rule: Proof

The Perceptron Learning Rule: Proof

The Perceptron Learning Rule: Proof

The Perceptron Learning Rule: Proof

The Perceptron Learning Rule: Proof

Limitations Of Perceptrons

Limitations Of Perceptrons

Summary

Rizoan Toufiq, Assistant Professor, Dept. of CSE, RUET

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• Perceptron-artificial neuron.
• Takes weighted sum of inputs, outputs t1 if greater than threshold else outputs 0.
• Hebbian learning (increasing effectiveness of active junctions) is predominant approach.
• Learning corresponds to adjusting the values of the weights.
• Feedforward supervised networks.
• Can use +1, -1 instead of 0 , l values.
• Can only solve problems that are linearly separable-therefore fails on XOR

Read Task

Rizoan Toufiq, Assistant Professor, Dept. of CSE, RUET

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B1: Neural Computing - An Introduction - R Beale and T Jackson, Publisher: Adam Hilger, 1990 IOP Publishing Ltd.

Chapter 3: The Basic Neuron

Query???

Rizoan Toufiq, Assistant Professor, Dept. of CSE, RUET

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