基于PSO-BFA和改进Alexnet的滚动轴承故障诊断方法

现实中滚动轴承的工况复杂易变,无法有效地对其进行故障诊断。对此,提出一种基于粒子群优化的细菌觅食(Particle Swarm Optimization and Bacterial Foraging Algorithm,PSO-BFA)和改进Alexnet(第二代卷积神经网络)的滚动轴承故障诊断方法。该方法将Alexnet的结构简化,并分别在其前两层池化层之后添置局部归一化层以降低训练成本;将以小批量样本softmax的交叉熵为损失函数,按Adam迭代优化法小样本、少迭代次数训练改进Alexnet后的变负荷样本诊断精度设计为适应度函数,并结合PSO中粒子移动速度的更新方法更新BFA中细菌的游动方向来寻找改进Alexnet的结构等相关参数;根据PSO-BFA所得的参数,以相同的训练方法大样本、多迭代次数训练改进Alexnet,实现复杂工况下滚动轴承多状态故障诊断。实验结果表明所提出的方法对复杂工况下滚动轴承16种故障状态的诊断是可行的,且有更高的诊断精度、更好的抗干扰和泛化性能。     

基于Alexnet网络的绝缘子自爆无人机巡检技术研究

绝缘子是输电系统中与安全相关的关键部件,绝缘子自爆问题的高效快速识别对电力系统的保护具有重要的意义。随着无人机（UAV）相关产业的不断发展,可以采用无人机技术对输电线路进行巡检拍摄。以此为背景提出了一种基于Alexnet网络的绝缘子自爆无人机巡检技术。首先,应用无人机巡检这一先进技术得到绝缘子的清晰实时图片。然后,采用Alexnet网络对绝缘子自爆图片进行学习和识别。与传统的识别方法相比,Alexnet网络模型不但结构上有所加深,对卷积的功能也进行了强化,对无人机巡检过程中拍摄的复杂图像进行识别和检测有很好的效果。     

Comparative analysis of Alzheimer's disease classification by CDR level using CNN,feature selection,and machine-learning techniques

Magnetic resonance imaging (MRI) of brain needs an impeccable analysis to investigate all its structure and pattern. This analysis may be a sharp visual analysis by an experienced medical professional or by a computer aided diagnosis system that can help to predict, what may be the recent condition. Similarly, on the basis of various information and technique, a system can be designed to detect whether a patient is prone to Alzheimer's disease or not. And this task of detection of abnormalities at an initial stage from brain MRI is a major challenge in the field of neurosciences. The main idea behind our research is to utilize the deep layers feature extraction benefited from deep neural network architecture, without extensive hardware resource training, and classifying the image on a basis of simple machine-learning algorithm with selected best features in order to reduce work load, classification error and hardware utilization time. We have utilized convolution neural network (CNN) layer using similar architecture like that of Alexnet with some parametric change, for the automatic extraction of features of images obtained from slice extraction of whole brain MRI whereas 13 manual features based on gray level co-occurrence matrix were also extracted to test the impact of this features on ranking. If we had only classified using CNN network, the misclassification rate was much higher. So, feature selection is achieved with feature ranking algorithms like Mutinffs, ReliefF, Laplacian and UDFS and so on and also tested with different machine-learning techniques like Support Vector Machine, K-Nearest Neighbor and Subspace Ensemble under different testing condition. The performance of the result is satisfactory with classification accuracy around 98% to 99% with 7:3 ratio of random holdout partition of training to testing image sets and also with fivefolds of cross-validation on the same set using a standardized template.     

基于卷积神经网络的织物表面缺陷分类方法

针对织物缺陷检测时疵点种类繁多且传统人工检测方法漏检率高的问题,提出了一种基于卷积神经网络的织物表面缺陷分类方法。因卷积神经网络（CNN）训练时参数多、样本量大,且极易陷入过拟合,利用微调卷积神经网络模型Alexnet对织物疵点图像进行特征提取,初始化采用原网络的参数而非随机初始化参数;再针对特定目标下的训练样本对网络参数进行微调;最后利用softmax回归算法进行预测分类。分别用三种方法和两种织物进行测试,结果表明：针对特定目标微调后的Alexnet网络,在两类织物测试中均能达到95%以上的分类准确率。     

基于深度学习的服装丝缕平衡性评价系统

为解决虚拟试装中难以自动评价服装丝缕平衡性的问题,充分应用了深度学习在图像自动识别中的优越性,针对服装丝缕平衡的特点,设计了卷积神经网络的拓扑结构,通过对各个特征部位上不同平衡状态的服装丝缕图片进行等级分类和学习训练,得到的网络模型的识别准确率达到93.589%,从而建立了可实现对服装各个关键部位丝缕平衡性自动评价系统。结果表明:应用基于深度学习的服装丝缕平衡性评价系统,对虚拟环境下的服装各个关键部位上的丝缕图片进行识别和分类,可以缩短服装平衡性检测的时间,提高检测的效率,快速获取服装丝缕不平衡的位置,以便对服装进行修改。