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The dynamic and static characteristics of hydrostatic thrust bearings are significantly affected by the bearing surface topography. Previous studies on hydrostatic thrust bearings have focused on Gaussian distribution models of bearing surface topography. However, based on actual measurements, the non-Gaussianity of the distribution characteristics of bearing surface topography is clear. To accurately characterize the non-Gaussian distribution of bearing surface topography, the traditional probability density function of Gaussian distribution was modified by introducing Edgeworth expansion. The non-Gaussian surface was then reflected by two parameters: kurtosis and skewness. This had an effect on the static characteristics of hydrostatic thrust bearings with both circumferential and radial surface topographies. The comparison between the Gaussian distribution results and those of the non-Gaussian model showed that errors between the two models could reach more than 10%. Therefore, it is important to take into account the non-Gaussianity of bearing surface when discussing static characteristics of hydrostatic thrust bearings considering the surface topography. [ABSTRACT FROM AUTHOR]

The noise in an LED chip image directly affects its visual positioning accuracy and efficiency. The existing denoising method can improve the image visual quality after removing the noise, but the improvement of the recognition rate and the positioning accuracy of the chip is not apparent. To solve this problem, this paper proposes a convolutional neural network combined with generative adversarial networks framework, the (CNN-GAN-GAN)-based blind denoiser, comprising three subnetworks. First, a noise extraction subnetwork with the proposed adaptive residual dense block extracts noise information from noisy images. Then, the noise modeling subnetwork with a dual-discriminator learns the noise distribution and constructs a paired training dataset. Finally, the blind denoising subnetwork with a hybrid loss function is trained for denoising. Contrast experiments show the proposed method can effectively suppress image noise and artifacts and meet the requirements of LED chip visual positioning accuracy while ensuring chip recognition rate. [ABSTRACT FROM AUTHOR]