Building a Deep Learning Model Uses CT Images for Covid-19 Diagnosis
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Lung CT images which are taken from Tongji Hospital, Wuhan, China for January 2020, and April 2020 are analyzed
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The whole image dataset consists of 349 CT images from 296 patients diagnosed with Covid-19 and 397 CT images from non-covid patients
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The images are resized to train the model faster as 100x100 and converted into torch tensors
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The whole dataset is splitted into train, validation, and test datasets



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A convolutional neural network with 3 convolutional and 3 pooling layers, and a final fully connected layer is used
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Batch normalization after convolutional layers are applied to speed up training
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ReLU activation function is used after hidden layers to eliminate vanishing gradient problem
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Softmax activation function in final layer to turn the vector into probabilities that sum up to 1
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Cross entropy loss function is chosen since it is wiser to use it in classification problems
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Adam and SGD optimizers are used
Neural Style Art Transfer
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Neural Style algorithm developed by Leon A. Gatsy, Alexander S.Ecker and Matthias Bethge is applied
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Neural style is creating an image which has the content of an image and a style of another image
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The key technique used in neural style transfer is convolutional neural network
- Two different pictures are taken from the internet and required preprocessing steps are taken
- They are resized to same shape as 512x512
- Converted into tensors
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The loss functions for both content and style are defined
- 19-layer VGG network is used
- Adam and SGD optimizers are both applied, and it is observed that results by Adam optimizer are better
- After performing neural transfer with different learning rates, number of epochs, and weights for content and style, final output which is the combination of 2 input images is obtained
- Since the quality of an image is subjective, it is hard to evaluate the performance of the neural style transfer. Thus, the results are not interpreted in a quantitative manner



Chest X-Ray Pneumonia Classification
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5856 chest X-ray images are used
- Three research questions which are tried to be answered:
- Do different networks result similar/same performance?
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Does applying transfer learning influence performance?
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Does using deep networks without pretraining on ImageNet have similar performance with the pretrained version?
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Data preprocessing methods are conducted to have better results in further modeling studies.
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Different models are run and finally, the models are evaluated with appropriate metrics and the results are interpreted accordingly
- Future works:
- To use a source dataset which is in the similar domain with the target dataset during transfer learning
- To increase the number of images is data augmentation
- To train the deep networks partially


