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Yan L.,Key Laboratory of Resources and Environment Information Engineering in Jiangsu Province | Yan L.,China University of Mining and Technology | Gao J.,Key Laboratory of Resources and Environment Information Engineering in Jiangsu Province | Gao J.,China University of Mining and Technology | And 4 more authors.
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/ Geomatics and Information Science of Wuhan University | Year: 2010

The uncertainly of artificial mark locations in digital photogrammetry is badly affected by imaging system. Aiming at mark location models with overlapped zero-mean Gaussian white noise and considering the physical process of imaging, a theoretical error performance Cramér-Rao lower bound based on the uncertainty theory of mark location was derived through the theory of maximum likelihood estimation. And its corresponding confidence interval was also determined on a certain confidence level. With the same confidence level, the uncertainty of any practical locations operator can be estimated with the degree of closeness between its own confidence interval and theoretical confidence interval of CRLB. To assess the uncertainty of practical locations operator and design a new more precise mark locations operator, circular mark is taken as an example to illustrate the effects of noise level and mark size on CRLB. The results show that the precision based on CRLB can be achieved 0.015 pixel by choosing suitable mark radius and small noise standard deviation. Source


Deng K.-Z.,China University of Mining and Technology | Deng K.-Z.,Key Laboratory of Resources and Environment Information Engineering in Jiangsu Province | Tan Z.-X.,China University of Mining and Technology | Tan Z.-X.,Key Laboratory of Resources and Environment Information Engineering in Jiangsu Province | And 6 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

On the basis of analyzing the mechanism of residual subsidence of old goaf, the model of calculating residual subsidence of gobs was deduced by combining the results of ruptured rock mass. Meanwhile the relationship were analyzed between the coefficient of residual subsidence and the characteristic of overburden strata, mining thickness, mining depth and building load. The research results show that while mining thickness is same, the shallower mining depth is, the larger coefficient of residual subsidence is, and there is larger surface residual subsidence in the future; While mining depth is same, the larger mining thickness is, the smaller coefficient of residual subsidence is; When the propotion of constuction loads to overburden stress is the same, the smaller the mining depth is, the larger the augmenter of subsidence coefficient is, and has more effect old goafs. Source

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