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Multi Layer PerceptronComputer & Robot Vision Lab
Sung -ju Kim [email protected]
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Content
• Why Neural Net came back?
• Single Layer Perceptron
• Multi Layer Perceptron
• Traffic Sign Lane Guessing
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Why Neural Net Came back?
Stallkamp, Johannes, et al. "Man vs. computer: Benchmarking machine learning algorithms for traffic sign recognition." Neural networks 32 (2012): 323-332.
Face net: 99.6% Deep Face : 97.25%
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Single Layer PerceptronFeed Forward
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Activation Functionsstep function sign function identity function
sigmoid function hyper tangent function
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Limitation of Single Layer Perceptron
But Single Layer Perceptron cannot classify XOR Problem
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Multi Layer Perceptron
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Multi Layer Perceptron
Hidden Layer
Output Layer
Input Layer
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Ex)
✕✕
Feed Forward
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How to Learn Perceptron?Error Function
Error Function
Target Value
Output Value
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How to Learn Perceptron?Delta Learning Rule
E
(weight)
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How to Learn Perceptron?Delta Learning Rule
new weightcurrent weightlearning rateError Function
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How to Learn Perceptron?Delta Learning Rule
E
(weight)
new weightcurrent weightlearning rateError Function
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Back Propagation
Hidden Layer
Output Layer
Input Layer
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new weight
current weight
learning rate
Error Function
Target Value
Output Value
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Back Propagation
Hidden Layer
Output Layer
Input Layer
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new weight
current weight
learning rate
Error Function
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Good for Design in Parallels Architecture