基于经验模式分解和一维密集连接卷积网络的电液换向阀内泄漏故障诊断方法

内泄漏作为电液换向阀常见的故障类型,其故障振动信号具有非平稳性、非线性等特点,且容易被其他信号淹没、破坏。对此提出了一种经验模式分解(Empirical Mode Decomposition,EMD)和一维密集连接卷积网络(Densely Connected Convolutional Networks,DenseNet)的电液换向阀内泄漏故障诊断方法。该方法首先利用EMD对振动信号进行分解得到一系列本征模态分量(Instrinsic Mode Function,IMF),并将IMF分量和原始振动信号依次进行并联堆叠;然后将并联堆叠信号作为一维密集连接卷积网络的输入进行特征的自动提取,并进行故障分类;最后通过DenseNet与传统的一维卷积神经网络(CNN)对比验证得出,该方法能准确、有效地对电液换向阀内泄漏故障进行诊断。     

基于深度学习优化SSD算法的硅片隐裂检测识别

针对传统的通过机器视觉和机器学习算法检测识别硅片隐裂所存在的精度低、识别率差、检测耗时长的问题,提出一种新的检测方法,即采用优化的单个深度神经网络来检测图像中的目标的方法 (Single Shot MultiBox Detector,SSD),对SSD的特征提取网络融合了密集连接卷积网络(Densely Connected Convolutional Networks,Dense Net),解决了原网络对低于0. 1 mm的裂痕提取困难的缺点。通过实验,优化后的SSD检测算法对低于0. 01 mm裂纹检测精度比传统的通过纹理滤波和SVM分类检测算法提高了22%,比没有优化的SSD算法检测准确率提高了6%。证明了本文作者所提方法的有效性。     

Detection of microscopic glaucoma through fundus images using deep transfer learning approach

Glaucoma disease in humans can lead to blindness if it progresses to the point where it affects the oculus' optic nerve head. It is not easily detected since there are no symptoms, but it can be detected using tonometry, ophthalmoscopy, and perimeter. However, advances in artificial intelligence approaches have permitted machine learning techniques to diagnose at an early stage. Numerous methods have been proposed using Machine Learning to diagnose glaucoma with different data sets and techniques but these are complex methods. Although, medical imaging instruments are used as glaucoma screening methods, fundus imaging specifically is the most used screening technique for glaucoma detection. This study presents a novel DenseNet and DarkNet combination to classify normal and glaucoma affected fundus image. These frameworks have been trained and tested on three data sets of high-resolution fundus (HRF), RIM 1, and ACRIMA. A total of 658 images have been used for healthy eyes and 612 images for glaucoma-affected eyes classification. It has also been observed that the fusion of DenseNet and DarkNet outperforms the two CNN networks and achieved 99.7% accuracy, 98.9% sensitivity, 100% specificity for the HRF database. In contrast, for the RIM1 database, 89.3% accuracy, 93.3% sensitivity, 88.46% specificity has been attained. Moreover, for the ACRIMA database, 99% accuracy, 100% sensitivity, 99% specificity has been achieved. Therefore, the proposed method is robust and efficient with less computational time and complexity compared to the literature available.     

基于DenseNet的低分辨CT影像肺腺癌组织学亚型分类

为了实现在低剂量、低分辨率CT扫描影像中对肺腺癌组织学亚型的分类鉴别,提出一种基于DenseNet的深度学习方法,从混合性磨玻璃结节（mGGNs）5 mm层厚的低分辨率CT影像中预测IAC和MIA病理分类. 从丽水市中心医院105例患者的105个5 mm层厚低分辨率CT图像中选取样本,划分训练集和测试集后,对训练集进行数据扩展,构建深度学习2D和3D DenseNet模型,分类鉴别IAC和MIA. 2D DenseNet模型的分类准确度为76.67%,敏感性为63.33%,特异性为90.00%,受试者工作特征曲线下的区域面积为0.888 9,显著优于3D DenseNet模型和其他几种深度学习网络模型. 深度学习技术,尤其是2D DenseNet模型,可辅助并指导医生在肺癌CT筛查中对患者的肺腺癌组织学亚型进行预判,特别是在图像分辨率较低的情况下,仍能够快速提供较为准确的诊断.     

Automatic Detection of Aortic Dissection Based on Morphology and Deep Learning

Aortic dissection (AD) is a kind of acute and rapidly progressing cardiovascular disease. In this work, we build a CTA image library with 88 CT cases, 43 cases of aortic dissection and 45 cases of health. An aortic dissection detection method based on CTA images is proposed. ROI is extracted based on binarization and morphology opening operation. The deep learning networks (InceptionV3, ResNet50, and DenseNet) are applied after the preprocessing of the datasets. Recall, F1-score, Matthews correlation coefficient (MCC) and other performance indexes are investigated. It is shown that the deep learning methods have much better performance than the traditional method. And among those deep learning methods, DenseNet121 can exceed other networks such as ResNet50 and InceptionV3.     

Big Data Analytics: Deep Content-Based Prediction with Sampling Perspective

The world of information technology is more than ever being flooded with huge amounts of data, nearly 2.5 quintillion bytes every day. This large stream of data is called big data, and the amount is increasing each day. This research uses a technique called sampling, which selects a representative subset of the data points, manipulates and analyzes this subset to identify patterns and trends in the larger dataset being examined, and finally, creates models. Sampling uses a small proportion of the original data for analysis and model training, so that it is relatively faster while maintaining data integrity and achieving accurate results. Two deep neural networks, AlexNet and DenseNet, were used in this research to test two sampling techniques, namely sampling with replacement and reservoir sampling. The dataset used for this research was divided into three classes: acceptable, flagged as easy, and flagged as hard. The base models were trained with the whole dataset, whereas the other models were trained on 50% of the original dataset. There were four combinations of model and sampling technique. The F-measure for the AlexNet model was 0.807 while that for the DenseNet model was 0.808. Combination 1 was the AlexNet model and sampling with replacement, achieving an average F-measure of 0.8852. Combination 3 was the AlexNet model and reservoir sampling. It had an average F-measure of 0.8545. Combination 2 was the DenseNet model and sampling with replacement, achieving an average F-measure of 0.8017. Finally, combination 4 was the DenseNet model and reservoir sampling. It had an average F-measure of 0.8111. Overall, we conclude that both models trained on a sampled dataset gave equal or better results compared to the base models, which used the whole dataset.     

基于注意力神经网络的糖尿病视网膜病变识别

针对目前糖尿病视网膜病变识别主要依赖于医生的临床经验,病变特征难以用肉眼区分且识别率较低等问题,提出一种基于注意力神经网络的糖尿病视网膜病变分类方法。首先,对原始数据集中的视网膜图像进行归一化、直方图均衡化和数据增强等预处理;其次,调整经典的DenseNet,在避免梯度消失和保证分类精度的前提下,有针对性地减少连接数,提出了2-DenseNet,同时将注意力模块嵌入到2-DenseNet中,指导网络关注视网膜图像中的渗出物、厚血管和微动脉瘤等特征,使用改进后的网络对预处理后的图像进行训练并测试;最后,在公开的Kaggle数据集上对多个网络进行对比,实验结果表明,该网络对糖尿病视网膜病变的分类性能高于其他对比网络。     

基于3D CNN的肺结节假阳性筛查模型

通过肺部CT影像进行肺结节检测是肺癌早期筛查的重要手段,而候选结节的假阳性筛查是结节检测的关键部分。传统的结节检测方法严重依赖先验知识,流程繁琐,性能并不理想。在深度学习中,卷积神经网络可以在通用的学习过程中提取图像的特征。该文以密集神经网络为基础设计了一个三维结节假阳性筛查模型—三维卷积神经网络模型(TDN-CNN)。首先利用U-Net提取CT图像的肺实质再截取以结节为中心的VOI,通过平移和翻转扩充正样本数据;在3维假阳性筛查网络中,通过稠密连接强化特征利用、扩大特征空间,采用瓶颈层降低参数冗余,训练中优化参数,最终获取最优模型。与2D CNN相比,该模型充分利用了肺结节的三维空间特征。该3D CNN在公开的LIDC数据集上的CPM得分达到0.840,显著高于其他几种3D模型。实验结果证明了该模型的有效性,其适用于肺结节的假阳性筛查。