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Sách Deep Learning cơ bản

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12 Các kỹ thuật cơ bản trong deep learning . . . . . . . . . . . . . . . . . . . . . 163

12.1 Vectorization 163

12.2 Mini-batch gradient descent 164

12.2.1 Mini-batch gradient descent là gì . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

12.2.2 Các thông số trong mini-batch gradient descent . . . . . . . . . . . . . . . . . . . . . 166

12.3 Bias và variance 167

12.3.1 Bias, variance là gì . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

12.3.2 Bias, variance tradeoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

12.3.3 Đánh giá bias and variance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

12.4 Dropout 169

12.4.1 Dropout là gì . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

12.4.2 Dropout hạn chế việc overfitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

12.4.3 Lời khuyên khi dùng dropout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

12.5 Activation function 170

12.5.1 Non-linear activation function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

12.5.2 Vanishing và exploding gradient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

12.5.3 Một số activation thông dụng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

12.6 Bài tập 174

VI

Computer Vision Task

13 Object detection với Faster R-CNN . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

13.1 Bài toán object detection 177

13.2 Faster R-CNN 178

13.2.1 R-CNN (Region with CNN feature) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

13.2.2 Fast R-CNN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

13.2.3 Faster R-CNN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

13.3 Ứng dụng object detection 187

13.4 Bài tập 187

14 Image segmentation với U-Net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

14.1 Bài toán image segmentation 189

14.1.1 Phân loại bài toán image segmentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

14.1.2 Ứng dụng bài toán segmentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

14.2 Mạng U-Net với bài toán semantic segmentation 192

14.2.1 Kiến trúc mạng U-Net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

14.2.2 Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

14.3 Bài tập 196

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