Interstitial Lung Disease (ILD) segmentation labels are highly costly, leading to small sample sizes in existing datasets and resulting in poor performance of trained models. To address this issue, a segmentation algorithm for ILD based on multi-task learning was proposed. Firstly, a multi-task segmentation model was constructed based on U-Net. Then, the generated lung segmentation labels were used as auxiliary task labels for multi-task learning. Finally, a method of dynamically weighting the multi-task loss functions was used to balance the losses of the primary task and the secondary task. Experimental results on a self-built ILD dataset show that the Dice Similarity Coefficient (DSC) of the multi-task segmentation model reaches 82.61%, which is 2.26 percentage points higher than that of U-Net. The experimental results demonstrate that the proposed algorithm can improve the segmentation performance of ILD and can assist clinical doctors in ILD diagnosis.
Federated Learning (FL) allows users to share and interact with multiple parties without directly uploading the original data, effectively reducing the risk of privacy leaks. However, existing research suggests that the adversary can still reconstruct raw data through shared gradient information. To further protect the privacy of federated learning, a deep shadow defense scheme of federated learning based on Generative Adversarial Network (GAN) was proposed. The original real data distribution features were learned by GAN and replaceable shadow data was generated. Then, the original model trained on real data was replaced by a shadow model trained on shadow data and was not directly accessible to the adversary. Finally, the real gradient was replaced by the shadow gradient generated by the shadow data in the shadow model and was not accessible to the adversary. Experiments were conducted on CIFAR10 and CIFAR100 datasets for comparison of the proposed scheme with the five defense schemes of adding noise, gradient clipping, gradient compression, representation perturbation and local regularization and sparsification. On CIFAR10 dataset, the Mean Square Error (MSE) and the Feature Mean Square Error (FMSE) of the proposed scheme were 1.18-5.34 and 4.46-1.03×107 times, and the Peak Signal-to-Noise Ratio (PSNR) of the proposed scheme was 49.9%-90.8%. On CIFAR100 dataset, the MSE and the FMSE of the proposed scheme were 1.04-1.06 and 5.93-4.24×103 times, and the PSNR of the proposed scheme was 96.0%-97.6%. Compared with the deep shadow defense method, the proposed scheme takes into account the actual attack capability of the adversary and the problems in shadow model training, and designs threat models and shadow model generation algorithms. It performs better in theory analysis and experiment result that of the comparsion schemes, and it can effectively reduce the risk of federated learning privacy leaks while ensuring accuracy.
To meet the application demand of high speed scanning and massive data transmission in industrial Computed Tomography (CT) of low-energy X-ray, a system of high-speed data acquisition and transmission for low-energy X-ray industrial CT was designed. X-CARD 0.2-256G of DT company was selected as the detector. In order to accommodate the needs of high-speed analog to digital conversion, high-speed time division multiplexing circuit and ping-pong operation for the data cache were combined; a gigabit Ethernet design was conducted with Field Programmable Gate Array (FPGA) selected as the master chip,so as to meet the requirements of high-speed transmission of multi-channel data. The experimental result shows that the speed of data acquisition system reaches 1MHz, the transmission speed reaches 926Mb/s and the dynamic range is greater than 5000. The system can effectively shorten the scanning time of low energy X-ray detection, which can meet the requirements of data transmission of more channels.