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Global position systems (GPS) receiver based on least mean square (LMS) could resist the interference by null jamming direction. Considering that the existing band-limited Gaussian noise jamming signals were easily suppressed by LMS-based GPS receivers, a time domain random flicker band-limited Gaussian noise jamming algorithm was proposed to improve its performance. By disturbing the convergence of LMS, it could achieve the purpose of suppressing the LMS-based GPS. Simulation result shows that the proposed algorithm has an average performance gain of 2.7dB~4.6dB under different number of interferences compared with band-limited Gaussian noise.

As the most common malignancy in the endocrine system, thyroid cancer is usually diagnosed by discriminating the malignant nodules from the benign ones using ultrasonography, whose interpretation results primarily depends on the subjectivity judgement of the radiologists. In this study, we propose a novel cascade deep learning model to achieve automatic objective diagnose during ultrasound examination for assisting radiologists in recognizing benign and malignant thyroid nodules. First, the simplified U-net is employed to segment the region of interesting (ROI) of the thyroid nodules in each frame of the ultrasound image automatically. Then, to alleviate the limitation that medical training data are relatively small in size, the improved Conditional Variational Auto-Encoder (CVAE) learning the probability distribution of ROI images is trained to generate new images for data augmentation. Finally, ResNet50 is trained with both original and generated ROI images. As consequence, the deep learning model formed by the trained U-net and trained Resnet-50 cascade can achieve malignant thyroid nodule recognition with the accuracy of 87.4%, the sensitivity of 92%, and the specificity of 86.8%.

The damping property of viscoelastic dampers is mainly based on the shear hysteretic behaviorof viscoelastic materials, so as to reduce the dynamic response of viscoelastic materials. Therefore, theviscoelastic damping properties of viscoelastic materials greatly affect the viscoelastic dampers. At present, viscoelastic materials mainly use rubber materials, but in this thesis, the excellent properties of polyurethaneelastomer materials are used to replace rubber materials and applied to viscoelastic dampers. However, purepolyurethane elastomer damping properties are related to poor performance, so it should be modified. Basedon the research of inorganic filler-modified polyurethane elastomer, the research group modified the threekinds of organic chemicals with hydroxyl silicone oil, HTPB liquid rubber and epoxy resin E-51, in the lowfrequency region of 0.025Hz-1.5Hz through the dynamic load test machine to test the dampingperformance.