Analysis and design cannot be solved until a proper model of hydraulic control system of earth pressure balance shield machine is built. There are two kinds of modeling methods in common use. (1) Dynamic mathematical modeling. Two models, transfer function and state space, are mainly included. For linear system, the two methods can be provided with a fairly complete theoretical framework. However, if the system is in the complicated working environment or it is non-linear, the modeling process needs a mass of mathematical verification. This has become a limitation for application of these methods; (2) Graphical Modeling. It is more direct for the complex hydraulic control system of earth pressure balance shield machine. First, the main components are separately modeled. Then connect them according to the flow direction of signal. Some special software, such as AMESim, can be used to simplify the simulation process.

An important feature of batch process data is that many batch processes have multiple phases. Many different phased-based monitoring methods had been proposed. The key question of those methods is how to divide the phases of batch process. However, PCA-based methods of phase division that identify phases by extracting the first principal component of each time slice lead easily to high misclassification. In order to overcome the shortcoming of PCA-based methods, a novel phase-division method based on dissimilarity index is proposed. In proposed division method, integral information of each time slice is used to divide phases. The phase-based PCA is built in each phase to monitoring Penicillin fermentation process in order to verify performance of proposed method. The simulation results show that the proposed method is able to detect process faults more prompt and accurate than single MPCA model.

Target position is a critical step in the process of constructing Delaunay triangulation. This paper establishes an improved incremental insertion method which realizes fast location based on moving center of gravity along the search direction. It is effective to solve unstable searching path problem usually occurring in some special cases, such as the line from target point to current center of gravity passes through a vertex of a triangle or coincides with a triangle edge. Simulation results show that there exists only location path using this method and the constructing efficiency is increased.

Based on multi-resolution analysis of wavelet, this article is aimed at building a new soft threshold function for wavelet de-noising, to overcome the discontinuous disadvantage of the hard threshold function. In the area adjacent to the threshold, continuously adjustable nonlinear functions are introduced in piecewise to process the wavelet coefficients more carefully in this area. Consequently, large deviation caused by super-compression of wavelet coefficients when using traditional soft threshold could be avoided, and the nonlinearity of the system is able to be effectively kept. Using both signal to noise ratio (SNR) and mean square error (MSE) as the evaluation indicators, simulation results show that the improved method is more effective than the method based on traditional hard and soft threshold.

Abstract. In this paper, an improved soft-threshold function is constructed, combined the improved function and empirical mode decomposition (EMD) methods, a new de-noising method has been proposed. Set the adaptive threshold for the intrinsic mode functions (IMFs) of the EMD, and then de-noise the each IMF respectively. Finally, the de-noised signal is reconstructed by the de-noised IMF components. Through the simulation results of quantitative analysis by signal-to-noise ratio (SNR) and mean square error (MSE), the algorithm in this paper has better de-noising effect. Also, this method can effectively improve the constant deviation between the original signal and the de-noised signal by traditional soft-threshold.