General and Vocational Tracks and Equity of Higher Education Enrollment Opportunities among Classes: A Reconstruction of Indicator System for Social Class-based Differential Enrollment Opportunities and its Empirical Analysis

Based on the educational hierarchical reproduction theory and the MMI and EMI hypotheses, this paper discusses the impact of the tracking of general and vocational education at the secondary level on higher education opportunity equity among social classes. The study finds that increasing gross enrollment rates of both general high schools and secondary vocational schools can help improve the equity in admission opportunities of colleges and universities among social strata; expanding the share of general high school places by adjusting the structure of general and vocational tracks (that is, the general-vocational ratio) can effectively reduce the class disparities in college and university admission opportunities; neither the change in the scale nor in the structure of general and vocational tracks will contribute to alleviating class inequality in top university enrollment opportunities

Research on parallel nonlinear control system of PD and RBF neural network based on U model

The modelling problem of nonlinear control system is studied, and a higher generality nonlinear U model is established. Based on the nonlinear U model, RBF neural network and PD parallel control algorithm are proposed. The difference between the control input value and the output value of the neural network is taken as the learning target by using the online learning ability of the neural network. The gradient descent method is used to adjust the PD output value, and ultimately track the ideal output. The Newton iterative algorithm is used to complete the transformation of the nonlinear model, and the nonlinear characteristic of the plant is reduced without loss of modelling precision, consequently, the control performance of the system is improved. The simulation results show that RBF neural network and PD parallel control system can control the nonlinear system. Moreover, the control system with Newton iteration can improve the control effect and anti-interference performance of the system