The reliability assessment problem for products subject to degradation and random shocks is investigated. Two kinds of probabilistic models are constructed, in which the dependent competing failure process is consider...The reliability assessment problem for products subject to degradation and random shocks is investigated. Two kinds of probabilistic models are constructed, in which the dependent competing failure process is considered. First, based on the assumption of cumulative shock, the probabilistic models for hard failure and soft failure are built respectively. On this basis, the dependent competing failure model involving degradation and shock processes is established. Furthermore, the situation of the shifting-threshold is also considered, in which the hard failure threshold value decreases to a lower level after the arrival of a certain number of shocks. A case study of fatigue crack growth is given to illustrate the proposed models. Numerical results show that shock has a significant effect on the failure process; meanwhile, the effect will be magnified when the value of the hard threshold shifts to a lower level.展开更多
The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified mode...The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified model and took the number of neighbors,neighbors' adoption and the cost-benefit parameters as crucial influencing factors.The diffusion of DaLingTong(CDMA450)products in MeiShan city of SiChuan province during 2004 to 2007 has been used to verity the model on Matlab.The validation results fit the actual diffusion pattern of DaLingTong(CDMA450) products very well.The results indicate that there exists a "tipping point(threshold)" in the process of innovation diffusion.If the initial adoption quantity is larger than the tipping point,then the product will spread to a large portion of people,otherwise is will collapse to zero.The model can effectively predict the diffusion of new products,and can influence the diffusion process by changing the value of the parameters.展开更多
基金The National Natural Science Foundation of China(No.50405021)Graduate Training Innovative Projects Foundation of Jiangsu Province(No.CXLX12_0081)
文摘The reliability assessment problem for products subject to degradation and random shocks is investigated. Two kinds of probabilistic models are constructed, in which the dependent competing failure process is considered. First, based on the assumption of cumulative shock, the probabilistic models for hard failure and soft failure are built respectively. On this basis, the dependent competing failure model involving degradation and shock processes is established. Furthermore, the situation of the shifting-threshold is also considered, in which the hard failure threshold value decreases to a lower level after the arrival of a certain number of shocks. A case study of fatigue crack growth is given to illustrate the proposed models. Numerical results show that shock has a significant effect on the failure process; meanwhile, the effect will be magnified when the value of the hard threshold shifts to a lower level.
基金ACKNOWLEDGEMENTS Project supported by the National Social Science Foundation of China （Grant No. 11BGL041）, Ministry of Education Humanities and Social Sciences General Project （12YJA630166）.
文摘The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified model and took the number of neighbors,neighbors' adoption and the cost-benefit parameters as crucial influencing factors.The diffusion of DaLingTong(CDMA450)products in MeiShan city of SiChuan province during 2004 to 2007 has been used to verity the model on Matlab.The validation results fit the actual diffusion pattern of DaLingTong(CDMA450) products very well.The results indicate that there exists a "tipping point(threshold)" in the process of innovation diffusion.If the initial adoption quantity is larger than the tipping point,then the product will spread to a large portion of people,otherwise is will collapse to zero.The model can effectively predict the diffusion of new products,and can influence the diffusion process by changing the value of the parameters.
