DR （diabetic retinopathy） is a most probable reason of blindness in adults, but the only remedy or escape from blindness is that we have to detect DR as early. Several automated screening techniques are used to dete...DR （diabetic retinopathy） is a most probable reason of blindness in adults, but the only remedy or escape from blindness is that we have to detect DR as early. Several automated screening techniques are used to detect individual lesions in the retina. Still it takes more dependency of time and experts. To overcome those problems and also automatically detect DR in easier and faster way, we took into soft computing approaches in our proposed work. Our proposed work will discuss several amounts of soft computing algorithms, it can detect DR features （landmark and retinal lesions） in an easy manner. Processes includes are： （1） Pre-processing; （2） Optic disc localization and segmentation; （3） Localization of fovea; （4） Blood vessel segmentation; （5） Feature extraction; （6） Feature selection; Finally （7） detection of diabetic retinopathy stages （mild, moderate, severe and PDR）. Our experimental results based on Matlab simulation and it takes databases of STARE and DRIVE. Proposed effective soft computing approaches should improve the sensitivity, specificity and accuracy.展开更多
Two-phase flow in two digital cores is simulated by the color-gradient lattice Boltzmann method.This model can be applied totwo-phase flow with high-density ratio(on order of 1000).The first digital core is an artific...Two-phase flow in two digital cores is simulated by the color-gradient lattice Boltzmann method.This model can be applied totwo-phase flow with high-density ratio(on order of 1000).The first digital core is an artificial sandstone core,and itsthree-dimensional gray model is obtained by Micro-CT scanning.The gray scale images are segmented into discrete phases(solid particles and pore space) by the Otsu algorithm.The second one is a digital core of shale,which is reconstructed usingMarkov Chain Monte Carlo method with segmented SEM scanning image as input.The wettability of solid wall and relativepermeability of a cylindrical tube are simulated to verify the model.In the simulations of liquid and gas two phase flow in digital cores,density ratios of 100,200,500 and 1000 between liquid and gas are chosen.Based on the gas distribution in the digital core at different times,it is found that the fingering phenomenon is more salient at high density ratio.With the density ratioincreasing,the displacement efficiency decreases.Besides,due to numerous small pores in the shale,the displacement efficiency is over 20% less than that in the artificial sandstone and the difference is even about 30% when density ratio is greaterthan 500.As the density ratio increases,the gas saturation decreases in big pores,and even reaches zero in some small pores orbig pores with small throats.Residual liquid mainly distributes in the small pores and the edge of big pores due to the wettability of liquid.Liquid recovery can be enhanced effectively by decreasing its viscosity.展开更多
文摘DR （diabetic retinopathy） is a most probable reason of blindness in adults, but the only remedy or escape from blindness is that we have to detect DR as early. Several automated screening techniques are used to detect individual lesions in the retina. Still it takes more dependency of time and experts. To overcome those problems and also automatically detect DR in easier and faster way, we took into soft computing approaches in our proposed work. Our proposed work will discuss several amounts of soft computing algorithms, it can detect DR features （landmark and retinal lesions） in an easy manner. Processes includes are： （1） Pre-processing; （2） Optic disc localization and segmentation; （3） Localization of fovea; （4） Blood vessel segmentation; （5） Feature extraction; （6） Feature selection; Finally （7） detection of diabetic retinopathy stages （mild, moderate, severe and PDR）. Our experimental results based on Matlab simulation and it takes databases of STARE and DRIVE. Proposed effective soft computing approaches should improve the sensitivity, specificity and accuracy.
基金supported by the National Natural Science Foundation of China(Grant No.51234007,51404291)Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT1294)Introducing Talents of Discipline to Universities(Grant No.B08028)
文摘Two-phase flow in two digital cores is simulated by the color-gradient lattice Boltzmann method.This model can be applied totwo-phase flow with high-density ratio(on order of 1000).The first digital core is an artificial sandstone core,and itsthree-dimensional gray model is obtained by Micro-CT scanning.The gray scale images are segmented into discrete phases(solid particles and pore space) by the Otsu algorithm.The second one is a digital core of shale,which is reconstructed usingMarkov Chain Monte Carlo method with segmented SEM scanning image as input.The wettability of solid wall and relativepermeability of a cylindrical tube are simulated to verify the model.In the simulations of liquid and gas two phase flow in digital cores,density ratios of 100,200,500 and 1000 between liquid and gas are chosen.Based on the gas distribution in the digital core at different times,it is found that the fingering phenomenon is more salient at high density ratio.With the density ratioincreasing,the displacement efficiency decreases.Besides,due to numerous small pores in the shale,the displacement efficiency is over 20% less than that in the artificial sandstone and the difference is even about 30% when density ratio is greaterthan 500.As the density ratio increases,the gas saturation decreases in big pores,and even reaches zero in some small pores orbig pores with small throats.Residual liquid mainly distributes in the small pores and the edge of big pores due to the wettability of liquid.Liquid recovery can be enhanced effectively by decreasing its viscosity.
