Intelligent back analysis of geotechnical parameters for time-dependent rock mass surrounding mine openings using grey Verhulst model

In this paper,we present a new method of intelligent back analysis(IBA)using grey Verhulst model(GVM)to identify geotechnical parameters of rock mass surrounding tunnel,and validate it via a test for a main openings of−600 m level in Coal Mine“6.13”,Democratic People's Republic of Korea.The displacement components used for back analysis are the crown settlement and sidewalls convergence monitored at the end of the openings excavation,and the final closures predicted by GVM.The non-linear relation between displacements and back analysis parameters was obtained by artificial neural network(ANN)and Burger-creep viscoplastic(CVISC)model of FLAC3D.Then,the optimal parameters were determined for rock mass surrounding tunnel by genetic algorithm(GA)with both groups of measured displacements at the end of the final excavation and closures predicted by GVM.The maximum absolute error(MAE)and standard deviation(Std)between calculated displacements by numerical simulation with back analysis parameters and in situ ones were less than 6 and 2 mm,respectively.Therefore,it was found that the proposed method could be successfully applied to determining design parameters and stability for tunnels and underground cavities,as well as mine openings and stopes.

Network Security Situation Prediction Based on Improved Adaptive Grey Verhulst Model

Network security situation is a hot research topic in the field of network security. Whole situation awareness includes the current situation evaluation and the future situation prediction. However, the now-existing research focuses on the current situation evaluation, and seldom discusses the future prediction. Based on the historical research, an improved grey Verhulst model is put forward to predict the future situation. Aiming at the shortages in the prediction based on traditional Verhulst model, the adaptive grey parameters and equal- dimensions grey filling methods are proposed to improve the precision. The simulation results prove that the scheme is efficient and applicable.

Industrial Engineering Analysis of Chinese Manufacturing Industry in Transition Period Based on Grey Predictions

In order to explore the characteristics and development strategies of Chinese manufacturing production system, the grey forecasting model GM( 1,1) and the grey verhulst dynamic model were built firstly. The prediction results show that Chinese manufacturing productivity would reach $ 32 806 per person in 2018,which indicates rapid development and lays the foundation for China to become the world's manufacturing power since the reform and opening up. However, it is predicted that Chinese manufacturing productivity would peak in 2018 based on the grey verhulst dynamic model,which reveals the resource configuration mode of Chinese manufacturing system could not prop up its increasing manufacturing capability. Furthermore the main reasons of this phenomenon were explored,which could be summarized as the lack of accumulation,integration of industrial engineering( IE)and information technology( IT), promoting mechanism of IE application as well as integration model of management innovation and technology innovation,etc. Finally,a series of strategies based on IE theory to solve these problems were given. This study provides an effective way to deal with the challenges and opportunities facing the Chinese manufacturing industry,meanwhile,it may contribute to the theoretical system of IE.