In the industrial field, the original fault signals collected during the operation of the equipment have the characteristics of strong noise and multiple working conditions. Most of previous data-driven fault diagnosis methods for bearings have relatively weak anti-noise ability and generalization ability. To solve these problems, a novel bearing fault diagnosis method based on down-sampling in frequency domain and convolutional neural network (CNN), called Ds-CNN, is proposed. Down-sampling in frequency domain consists of maximum down-sampling with bias and noise transverse truncation, which can realize data augmentation, reduce the difference between samples in frequency domain, and reduce the influence of noise on signals in frequency domain. The CNN model based on frequency domain signals can automatically extract fault features from signals after down-sampling and complete the identification and classification of bearing faults. The results of the experiment show that Ds-CNN has higher recognition accuracy than common models under strong noise environment and multiple working conditions. 

Aiming at the problem of LOD (level of detail) popping and aliasing when the LOD Level is switched, this paper proposes a shader-based smooth transition algorithm for LOD texture blending and antialiasing. According to the distance between the 3D model and the viewpoint, the opaque mask algorithm based on Alpha test and weighted adjacent frames antialiasing algorithm are used to generate transition materials between LODs to achieve smooth transition for LOD switching. It can not only improve the texture quality, but also ensure the fluency and authenticity of loading 3D scene. The experimental results show that, compared with the smoothing method of Unreal Engine 4, the average GPU time of the proposed algorithm is reduced by more than 8%, and the frame rate is increased by more than 8%. Compared with the existing texture smooth transition methods, this algorithm can optimize the GPU rendering performance, stabilize and improve the frame rate and maintain good visual effect, effectively solve the popping problem when the LOD Level is switched.