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Overview

CVV_15M_SARS-CoV-2 is a convolutional neural network to classify chest X-ray images with high accuracy on mobile hardware. Finely tuned for performance on Apple M-series CPUs.

Key Features

Background & Methodology

The implementation incorporates ReLU activation functions, LRN, overlapping pooling, and dropout layers. The model can extract intricate patterns from X-ray images at a high degree of accuracy.

ReLU Activation Function

TensorFlow employs ReLU activations:

\[ f(x) = \max(0, x) \]

ReLU accelerates trainingon smaller datasets by preventing vanishing gradients and promoting sparse activations.

Local Response Normalization (LRN)

To enhance feature selectivity, our model implements LRN which ecourages higher competition among neurons:

\[ b_{i,x,y} = \frac{a_{i,x,y}}{\left(k + \alpha \sum_{j=\max(0,i-\frac{n}{2})}^{\min(N-1,i+\frac{n}{2})} (a_{j,x,y})^2 \right)^{\beta}} \]

LRN helps minimize redundancy in datasets with overlapping image features by reducing the impact of already learned features that should be omitted.

Overlapping Pooling

By using overlapping pooling regions (\( s < z \)), the model gains a spatial representation of the novelties in the X-rays.

Dropout Regularization

To counter overfitting, dropout (0.5 rate) is applied in the fully connected layers:

\[ P(h_j \mid x) = \sum_i P(h_j \mid i) P(i \mid x) \]

Mixed Precision Training

We implemented TensorFlow's mixed precision training policy to optimize computational efficiency:

This approach allows us to:

Implementation Details

Data Pipeline & Preprocessing

The model was trained on a dataset of 17,000 chest X-ray images across three categories.

Model Configuration

Our implementation leverages a carefully designed structure:

Performance & Results

Our model achieved >95% accuracy classifying among three categories:

Model Configuration

Image count: 17,000
IMAGE_SIZE: 224
BATCH_SIZE: 16
EPOCHS: 30
NUM_CLASSES: 3
Test accuracy: 0.9403

Confusion Matrix

Covid Normal Pneumonia
Covid 708 10 6
Normal 70 922 8
Pneumonia 11 14 244

Performance Analysis

Technology Stack

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