A new threshold function was proposed to overcome that hard threshold function is not continuous, soft threshold function has constant deviation and derivative discontinuity defects. It will be applied to using different thresholds denoising method with different decomposition level based on the D.J global threshold. Experimental results shows that the denoising result of new threshold function is superior to the traditional soft and hard threshold function in minimum mean square error (MSE) and peak signal to noise ratio (PSNR).

Abstract.The method of Delays is commonly used in state space reconstruction of chaotic time series, and the quality of attractor reconstruction of phase space is sensitive to the choice of embedding parameters, i.e. embedding dimension and time delay. In this paper, singular entropy (SE) is applied to choose the optimal time delay in reconstructed dynamical system, and the comparisons of relevant results are made with the correlation function method by using singular value fraction (SVF). The robustness of singular entropy algorithm is further discussed, and it shows the advantage of the proposed method. The reconstructed state of the system at each discrete time i is

According to the communication principle of 840D numerical control (NC) system and internal data structure, the PLC program is developed to make 840D system state data transmit to the PC with the MPI channels; production status data real-time monitoring system based on 840D NC machine tools is developed, meanwhile, the monitoring and data management for NC machine tool production process status is realized.