Recently, introducing a transition predicting model into the Reynolds averaged Navier-Stokes （RANS） environment has been paid more and more attention. Langtry proposed a correlation-based transition model in 2006, w...Recently, introducing a transition predicting model into the Reynolds averaged Navier-Stokes （RANS） environment has been paid more and more attention. Langtry proposed a correlation-based transition model in 2006, which was built strictly on local variables. However, two core correlations in the model had not been published until 2009. In this paper, after considerable analyses and discussions of the mechanism of this transition model and a series of numerical validations in the skin friction coefficient of flat plate boundary layers, a new correlation based on free-stream turbulence intensity is developed, and the empirical correlation of the transition onset momentum thickness Reynold number aiming at the hypersonic transition is improved. Low-speed/transonic airfoils and a hypersonic double wedge fiat are tested to prove the reliability and practicability of this correlation.展开更多
“Objective Correlative”theory was first proposed by T.S. Eliot, who holds that people’s emotion can find expression in a series of objective correlative. In his poem The Love Song of J.Alfred Prufrock, the use of o...“Objective Correlative”theory was first proposed by T.S. Eliot, who holds that people’s emotion can find expression in a series of objective correlative. In his poem The Love Song of J.Alfred Prufrock, the use of objective correlative fully reflects and reveals modern people’s loneliness, futility and alienation.展开更多
In order to promote the application of Beijing-1 small satellite(BJ-1) remote sensing data,the multispectral and panchromatic images captured by BJ-1 were used for land cover classification in Pangzhuang Coal Mining.A...In order to promote the application of Beijing-1 small satellite(BJ-1) remote sensing data,the multispectral and panchromatic images captured by BJ-1 were used for land cover classification in Pangzhuang Coal Mining.An improved Intensity-Hue-Saturation(IHS) fusion algorithm is proposed to fuse panchromatic and multispectral images,in which intensity component and panchromatic image are combined using the weights determined by edge pixels in the panchromatic image identified by grey absolute correlation degree.This improved IHS fusion algorithm outper-forms traditional IHS fusion method to a certain extent,evidenced by its ability in preserving spectral information and enhancing spatial details.Dempster-Shafer(D-S) evidence theory was adopted to combine the outputs of three member classifiers to generate the final classification map with higher accuracy than that by any individual classifier.Based on this study,we conclude that Beijing-1 small satellite remote sensing images are useful to monitor and analyze land cover change and ecological environment degradation in mining areas,and the proposed fusion algorithms at data and decision levels can integrate the advantages of multi-resolution images and multiple classifiers,improve the overall accuracy and produce a more reliable land cover map.展开更多
During T.S. Eliot's(1888-1965)whole life he left us a lot of fortune, and The Love Song of J. Alfred Prufrock is considered as one of Eliot's finest and most important works. A lot of scholars and critics have...During T.S. Eliot's(1888-1965)whole life he left us a lot of fortune, and The Love Song of J. Alfred Prufrock is considered as one of Eliot's finest and most important works. A lot of scholars and critics have done different researches on this poem.The author of this paper tries to analyze one of these poems from the perspective of T.S. Eliot's poetics.展开更多
This paper mainly talks about a popular approach of volatility of a GARCH-type model in R, while the disturbances are independent and have identical Student-t distribution. It uses the Metropolis-Hastings method to pe...This paper mainly talks about a popular approach of volatility of a GARCH-type model in R, while the disturbances are independent and have identical Student-t distribution. It uses the Metropolis-Hastings method to perform the computations and gives the programs in details in R.展开更多
文摘Recently, introducing a transition predicting model into the Reynolds averaged Navier-Stokes （RANS） environment has been paid more and more attention. Langtry proposed a correlation-based transition model in 2006, which was built strictly on local variables. However, two core correlations in the model had not been published until 2009. In this paper, after considerable analyses and discussions of the mechanism of this transition model and a series of numerical validations in the skin friction coefficient of flat plate boundary layers, a new correlation based on free-stream turbulence intensity is developed, and the empirical correlation of the transition onset momentum thickness Reynold number aiming at the hypersonic transition is improved. Low-speed/transonic airfoils and a hypersonic double wedge fiat are tested to prove the reliability and practicability of this correlation.
文摘“Objective Correlative”theory was first proposed by T.S. Eliot, who holds that people’s emotion can find expression in a series of objective correlative. In his poem The Love Song of J.Alfred Prufrock, the use of objective correlative fully reflects and reveals modern people’s loneliness, futility and alienation.
基金Under the auspices of National Natural Science Foundation of China (No. 40871195)Opening Fund of Beijing-1Small Satellite Data Applications from State Key Laboratory for Remote Sensing Science (No. 200709)National High Technology Research and Development Program of China (No. 2007AA12Z162)
文摘In order to promote the application of Beijing-1 small satellite(BJ-1) remote sensing data,the multispectral and panchromatic images captured by BJ-1 were used for land cover classification in Pangzhuang Coal Mining.An improved Intensity-Hue-Saturation(IHS) fusion algorithm is proposed to fuse panchromatic and multispectral images,in which intensity component and panchromatic image are combined using the weights determined by edge pixels in the panchromatic image identified by grey absolute correlation degree.This improved IHS fusion algorithm outper-forms traditional IHS fusion method to a certain extent,evidenced by its ability in preserving spectral information and enhancing spatial details.Dempster-Shafer(D-S) evidence theory was adopted to combine the outputs of three member classifiers to generate the final classification map with higher accuracy than that by any individual classifier.Based on this study,we conclude that Beijing-1 small satellite remote sensing images are useful to monitor and analyze land cover change and ecological environment degradation in mining areas,and the proposed fusion algorithms at data and decision levels can integrate the advantages of multi-resolution images and multiple classifiers,improve the overall accuracy and produce a more reliable land cover map.
文摘During T.S. Eliot's(1888-1965)whole life he left us a lot of fortune, and The Love Song of J. Alfred Prufrock is considered as one of Eliot's finest and most important works. A lot of scholars and critics have done different researches on this poem.The author of this paper tries to analyze one of these poems from the perspective of T.S. Eliot's poetics.
文摘This paper mainly talks about a popular approach of volatility of a GARCH-type model in R, while the disturbances are independent and have identical Student-t distribution. It uses the Metropolis-Hastings method to perform the computations and gives the programs in details in R.
