An effective approach based on nonlinear spectrum and improved convolution neural network for analog circuit fault diagnosis.

In this work, an effective approach based on a nonlinear output frequency response function (NOFRF) and improved convolution neural network is proposed for analog circuit fault diagnosis. First, the NOFRF spectra, rather than the output of the system, are adopted as the fault information of the analog circuit. Furthermore, to further improve the accuracy and efficiency of analog circuit fault diagnosis, the batch normalization layer and the convolutional block attention module (CBAM) are introduced into the convolution neural network (CNN) to propose a CBAM-CNN, which can automatically extract the fault features from NOFRF spectra, to realize the accurate diagnosis of the analog circuit. The fault diagnosis experiments are carried out on the simulated circuit of Sallen-Key. The results demonstrate that the proposed method can not only improve the accuracy of analog circuit fault diagnosis, but also has strong anti-noise ability.

[Carrier screening for spinal muscular atrophy in 4719 pregnant women in Shanghai region].

OBJECTIVE: Spinal muscular atrophy (SMA) is a common and fatal autosomal recessive disorder. Approximately 94% of SMA patients are caused by homozygous deletion of SMN1 gene. SMA carrier screening is recommended considering the high carrier frequency (1 in 35-50) as well as severity of the disease. METHODS: A prospective population-based cohort study was carried out on 4719 pregnant women from Shanghai region. Copy numbers of SMN1 and SMN2 genes were effectively determined with denaturing high performance liquid chromatography (DHPLC) technique. The method has detected 94% of SMA cases with deletion or conversion of the SMN1 genes. RESULTS: Ninety SMA carriers with only one copy of the SMN1 gene were identified among the 4719 pregnant woman. The carrier rate was 1.9%. Respectively, 1.2% and 0.6% of the carriers were caused by SMN1 gene deletion and SMN1 gene conversion. CONCLUSION: Through this study, we have determined the frequency of SMA mutation carriers in a population of pregnant women. The result may provide a basis for genetic counseling in order to reduce the rate of SMA affected births.