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.
Grey System Theory and Applications: A Way Forward
Grey system theory was initiated in the beginning of 1980s. Since then the research on theory development and applications is progressing. However, until today nearly all researchers of grey system theory are from Chinese speaking areas, and the theory is still hardly known nor accepted in the western world. The paper addresses the state-of-the-art development of grey system theory and its application. It aims to highlight and analyse relevant issues (i.e. obstacles, possible solutions and potential trends) for further research from the perspective both of grey system theory and of the grey system methods.
Application of Grey System Theory in the Development of a Runoff Prediction Model
The mathematical models used for modelling hydrological processes generally require relatively long-time data series. For developing countries like India, one of the major problems is unavailability of reliable hydrological data for longer durations. An attempt has been made in present study to model the rainfall–runoff process by using grey system theory, a relatively new approach in the field of hydrology. Grey system theory advances an approach to investigate the relationship of an input–output process with unclear inner relationships, uncertain mechanisms and insufficient information. Sixteen storm events for Kothuwatari watershed of Tilaiya dam catchment, Jharkhand, India, collected for the years 1993–1997 have been used for development and prediction of differential hydrological grey models. A least-squares method has been employed for the estimation of model parameters. Performance of the developed model has been evaluated through the qualitative and quantitative statistical indices. Lower values of various error indices and higher values of correlation indices confirm the ability of the model to predict storm runoff with reasonable accuracy for the study area.