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Accurate height prediction has important reference significance for the development of children and adolescents and the selection of athletes. The current mainstream height prediction methods include the B-P (Bayley–Pinneau) method and the TW2 (Tanner–Whitehouse) method. A large number of documents show that the B-P method and the TW2 method have relatively large deviations in the lifelong height prediction results of Chinese children and adolescents. Based on the data collected by the Chinese Adolescent Students’ Physical Fitness and Growth and Development Health Project in Zhejiang’s primary and secondary schools, this paper proposes a graph of height growth trends based on bone age. The height map of age has more reference value. Aiming at the feasibility of the height data in the statistical results, the interpolation prediction method is used to verify the data, and the height growth trend graph is drawn through the method of fitting. Validation results with actual data show that the average error of the lifetime height prediction of the height growth trend map proposed in this paper is 2.1 cm, which is 1.4 cm lower than the 3.5 cm error predicted by the B-P method and 0.4 cm lower than the 2.5 cm error predicted by the TW2 method. more...

Pitch motion is a critical factor that affects the aerodynamic load of blades and the motion response of the floating platform. To study the effects of pitch motion, the NREL 5-MW is analyzed by using Computational Fluid Dynamics (CFD) method. The motion of the wind turbine and the floating platform is dealt with dynamic fluid–solid interaction technology. The mesh in the blade rotation domain and the motion domain are sliding mesh and overlapped mesh respectively. The Fluid Volume Fraction (VOF) method is utilized to generate and track the free surface of the ocean wave. By setting the frequencies and amplitudes of sinusoidal pitch motion, the distributed aerodynamic pressure coefficient of the cross-sections is studied along the blade spanwise direction, and the instantaneous thrust, the turbine power coefficient and the wake vortex structure are analyzed. For blade only cases, results show that the pressure coefficient near the leading edge of each spanwise blade section reaches a maximum at the half-cycle, and the turbine power output is in phase with the pitch motion. For fully coupled cases, both the frequency of the turbine thrust and pitch motion is determined by the incident wave but in a reversed phase. more...

This paper proposed a signal processing method based on principal component analysis (PCA) and wavelet analysis, aiming to reduce the dimension of the data and obtain both frequency and time localization information which could help to find abnormal phenomenon quickly and orient the position and the time of faults exactly in the complex textile machinery system. At first, the original signals were simplified by principal component transform, which was conducted by calculating the eigen value and eigenvector of correlation coefficient matrix, and by defining the first few PCs containing most of the variables according to contribute rate and cumulative contribute rate. Secondly, the restructured signals were decomposed into approximative and detailed ones for obtaining meaningful captures of instantaneous frequency by wavelet analysis. In this stage, Hilbert Envelope Analysis was also carried out to the first layer detail signal and to find its power spectrum. From practical application, this signal processing method was approved validated. more...