Notice of Retraction3-Dimensional Numerical Simulation Method for the Rock Slope Excavation in Civil Engineering
Rock slope is an unknown and complicated system; As for time series with strong randomization, application of the modified GM(1,1) was much more precise than ordinary GMs by comparison. And for time series with fluctuate positive and negative data, translation of the data and revivification after modeling was introduced to make an expansion of the application of the modified GM(1,1). The fitting and prediction precision was good by applying the modified GM(1,1) to analysis the monitoring stress of certain site of the left bank of Jinping Hydropower station. And by compassion, it was known that the prediction trend was accurate, and gave good ground work for further study. On the contrary, it was an important issue for the establishment of long-term prediction models.
Study and application of displacement time series forecast based on APSO-WLSSVM
The model of wavelet least squares support vector machines(WLSSVM) is optimized by adaptive particle swarm optimization(APSO),and a new model named as wavelet least squares support vector machine based on adaptive particle swarm optimization(APSO-WLSSVM) is put forward.The model combines good time domain,frequency domain resolving ability of wavelet transformation and nonlinear learning ability of SVM.The adaptive particle swarm optimization is used to optimize the parameters of SVM so as to avoid artificial arbitrariness and enhance the forecast accuracy.For comparison,the model of APSO-WLSSVM and the traditional SVM(Gauss kernel function) are used to forecast the same displacement time series.The result shows that the former is better than the latter in forecast accuracy.The model is used to forecast the left back slope and diversion tunnel of Jinping First-stage Hydropower Station.The forecast values are in good agreement with the measured ones,indicating that the APSO-WLSSVM is feasible and precise and can be well applied to the forecast of displacement time series.
Numerical Simulation of Induction Heating Process of Continuous Casting Slab
Compared with traditional blazing furnace, the Continuous Casting-Direct Rolling is an advanced manufacturing steel technology, which can reduce energy waste, decrease pollution and enhance efficiency. The characteristics of steels during induction heating are complex, the change of material properties with temperature makes exact analysis methods very difficult to implement. Therefore, a powerful computer aided numerical tool (i.e., finite difference analysis) is selected to numerically model the induction heating process in this paper. The mathematic model coupling with electromagnetic field and thermal field was established, and it was solved by finite difference method (FDM), thus the slab temperature distribution and its variation with time were obtained, and the characteristics in whole induction heating process were studied. To validate the program feasible, the results were evaluated and compared with experiment results, which showed that the simulation results are reliable and effective. The skin effect in heating process from the two results was studied and demonstrated, the temperature change caused by different parameters such as the induced power intensity and the corner radian were also presented, which indicate that the slab temperature can be heated uniformly through adjusting these parameters, thus the continuous casting slab can meet the rolling requirement.