r g.ai orkimlab.postech.ac.kr/dkim/class/csed703G_2020f/C1M4.pdf · 2020. 7. 17. · ork. w Ng? on...
Transcript of r g.ai orkimlab.postech.ac.kr/dkim/class/csed703G_2020f/C1M4.pdf · 2020. 7. 17. · ork. w Ng? on...
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deeplearning.ai
Deep NeuralNetworks
Deep L-layerNeural network
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AndrewNg
What is a deep neural network?
logistic regression
1 hidden layer
2 hidden layers
5 hidden layers
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AndrewNg
Deep neural network notation
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deeplearning.ai
Deep NeuralNetworks
Forward Propagationin a Deep Network
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AndrewNg
Forward propagation in a deep network
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deeplearning.ai
Getting your matrixdimensions right
Deep Neural Networks
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Andrew Ng
Parameters !["] and "["]
$%&!&"
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Andrew Ng
Vectorized implementation
!"#!#"
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deeplearning.ai
Whydeeprepresentations?
DeepNeuralNetworks
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AndrewNg
Intuition about deep representation
!"
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AndrewNg
Circuit theory and deep learningInformally: There are functions you can compute with a “small” L-layer deep neural network that shallower networks require exponentially more hidden units to compute.
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deeplearning.ai
Building blocks ofdeep neural networks
Deep NeuralNetworks
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AndrewNg
Forward and backward functions
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AndrewNg
Forward and backward functions
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deeplearning.ai
Parameters vsHyperparameters
Deep Neural Networks
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Andrew Ng
What are hyperparameters?Parameters: ! " , % " ,! & , % & ,! ' , % ' …
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Andrew Ng
Applied deep learning is a very empirical process
cost !
# of iterations
Idea
Experiment Code
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deeplearning.ai
What does thishave to do with
the brain?
Deep Neural Networks
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Andrew Ng
Forward and backward propagation!["] = #["]$ + &["]'["] = ( " (! " )![$] = #[$]'["] + &[$]'[$] = ( $ (! $ )
'[%] = ( % ! % = +,
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-![%] = '[%] − +-#[%] = 10-!
% ' % &
-&[%] = 1012. sum(d!% , 9:;< = 1, =>>2-;0< = ?@A>)
-![%'"] = -# % &-! % (( % (! %'" )
-#["] = 10-!" ' " &
-&["] = 1012. sum(d!" , 9:;< = 1, =>>2-;0< = ?@A>)
-!["] = -# % &-! $ (( " (! " )