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.
Research on the Optimization of Grey Model GM(1,1)
It is studied in this paper,that how the parameters \$a\$ and \$u\$ of grey model GM(1,1) worked up are affected by every datum of original series minus same constant \$2β\$, and which value of constant \$β\$ is found out so that the grey model is optimal in the sense of optimum fitting line.
Grey target theory based equipment condition monitoring and wear mode recognition
Abstract Grey target theory is a newly developed method in grey system theory. Calculating with grey target theory, pattern recognition, mode gradation and optimal mode selection can be performed. Oil samples from one auto press line and one 16V280ZJA diesel engine were analyzed by analytical ferrograph. For every wear particle in every analytical result, the size and quantity were quantified together. And some corresponding series have been established. Grey target theory was applied and a “bull's-eye” was constructed. By calculating the approaching degrees, wear modes have been graded, in conjunction with the running conditions of the press line and the diesel engine for given operation modes. The order of existing wear modes from severe to benign has also been assessed. The results agree with the experts’ analysis. This is the first time that grey target theory has been applied in oil monitoring for wear mode recognition.