anotasi
Sifat kotak hitam yang dirasakan dari jaringan saraf merupakan kendala untuk digunakan dalam aplikasi di mana interpretabilitas penting. Di sini kami menyajikan DeepLIFT (Deep Learning Important FeaTures), sebuah metode untuk mendekomposisi prediksi output jaringan saraf pada input tertentu dengan melakukan propagasi balik respons semua neuron (node) jaringan ke setiap fitur sinyal input. DeepLIFT membandingkan aktivasi setiap neuron dengan "aktivasi referensi" dan memberikan perkiraan kontribusi individualnya. Dengan mempertimbangkan kontribusi positif dan negatif secara terpisah, DeepLIFT juga dapat mengidentifikasi ketergantungan yang dilewatkan oleh pendekatan lain. Skor dapat dihitung secara efisien dalam satu kali pengembalian. Kami menerapkan DeepLIFT ke model yang dilatih MNIST dan simulasi data genom,menunjukkan keunggulan yang signifikan dibandingkan metode gradien.
Tutorial video: http://goo.gl/qKb7pL
Slide ICML: bit.ly/deeplifticmlslides
Pembicaraan ICML: https://vimeo.com/238275076
kode: http://goo.gl/RM8jvH
1. Perkenalan
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2.
.
2.1.
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2.2. ,
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2.2.1. , (, )
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2.2.2. ×
. (Bach et al., 2015 [1]) , (LRP). . Kindermans et al. (Shrikumar et al., 2016; Kindermans et al., 2016 [8]) , , , LRP ReLU Simonyan et al. ( , × ). DeepLIFT gradient × input, GPU, LRP GPU, .
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2.2.3.
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2.3. Grad-CAM CAM
Grad-CAM (Selvaraju et al., 2016 [7]) , , , , . ( ) , , Grad-CAM , , Grad-CAM. , . .
3. DeepLIFT
3.1. DeepLIFT
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-10. , x = 10; x = 10 + e, × 10 + e x -10 ( - ). x < 10, x 0. , ( , ) .
3.2.
3.2.1.
x ∆x t ∆t, , m∆x∆t :
, m∆x∆t - ∆x ∆t, ∆x. : ∂t / ∂x - ∆t, ∆x, ∆x. , .
3.2.2.
, x1, ..., xn, y1, ..., yn t.
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3.3.
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3.4.
3.5.3 , - . , y ∆y + ∆y−, ∆y, :
∆y+ ∆y− ∆y , ∆xi, . RevealCancel ( 3.5.3), t , m∆y + ∆t m∆y − ∆t . ( 3.5.1 3.5.2) : m∆y∆t = m∆y + ∆t = m∆y − ∆t.
3.5.
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3.5.1.
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:
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∆xi 0 ( ∆x-).
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3.5.2.
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3.5.3. : REVEALCANCEL
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3.6.
softmax , , . , , , 3.1. , o = (y), y - .
o 1, x1 x2 0,5 0 . , x1 = 100 x2 = 100, o - 1, x1 x2 0,25 . , DeepLIFT. , y, o.
Softmax
, softmax, softmax, , softmax , softmax - . , , . , n - ,
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4.
4.1. (MNIST)
MNIST (Le-Cun et al., 1999) Keras (Chollet, 2015) 99,2%. , , softmax (. D ). > 1 , , (Springenberg et al., 2014 [10]). DeepLift ( ).
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4.2. ()
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5.
DeepLIFT, , «» «» . (. 1), , , tanh. DeepLIFT ( * - . . 2). , DeepLIFT-RevealCancel , (. 3). : () DeepLIFT RNN,(b) (c) «» ( Maxout Maxpooling ) .
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