Yingjie Shao

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2. Results and Discussion 2.1. Denoising of the First Artificial Signal Figure 1a–e show the first artificial noised signal, the different cosine functions and random noise that construct the artificial signal. The frequency of the three functions from low to high, and the frequency of random noise is the highest. Ideally, the curves of b–d in Figure 1 can be clearly obtained after decomposition.