Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitions becomes popular as an alternative to the traditional federated architecture. This study investigates th...Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitions becomes popular as an alternative to the traditional federated architecture. This study investigates the problem of designing hierarchical scheduling for IMA systems. The proposed scheduler model enables strong temporal partitioning, so that multiple hard real-time applications can be easily integrated into an uniprocessor platform. This paper derives the mathematic relationships among parti- tion cycle, partition capacity and schedulability under the real-time condition, and then proposes an algorithm for optimizing partition parameters. Real-time tasks with arbitrary deadlines are considered for generality. To further improve the basic algo- rithm and reduce the energy consumption for embedded systems in aircraft, a power optimization approach is also proposed by exploiting the slack time. Experimental results show that the designed system can guarantee the hard real-time requirement and reduce the power consumption by at least 14%.展开更多
AIM:To evaluate the detectability of gallbladder stones by dual-energy spectral computed tomography(CT) imaging.METHODS:Totally 217 patients with surgically confirmed gallbladder stones were retrospectively analyzed w...AIM:To evaluate the detectability of gallbladder stones by dual-energy spectral computed tomography(CT) imaging.METHODS:Totally 217 patients with surgically confirmed gallbladder stones were retrospectively analyzed who underwent single-source dual-energy CT scanning from August 2011 to December 2013. Polychromatic images were acquired. And post-processing software was used to reconstruct monochromatic(40 ke V and 140 ke V) images,and calcium-lipid pair-wise base substance was selected to acquire calcium base images and lipid base images. The above 5 groups of images were evaluated by two radiologists separately with 10-year experience in CT image reading. In the 5 groups of images,the cases in the positive group and negative group were counted and then the detection rate was calculated. The inter-observer agreement on the scoring results was analyzed by Kappa test,and the scoring results were analyzed by Wilcoxon test,with P < 0.05 indicating that the difference was statistically significant. The stone detection results of the 5 groups of images were analyzed by χ2 test.RESULTS:There was good inter-observer agreement(k = 0.772). In 217 patients with gallbladder stones,there was a statistically significant difference in stone visualization between spectral images(40 ke V,140 ke V,calcium base and lipid base images) and polychromatic images(P < 0.05). 40 ke V monochromatic images were better than 140 ke V monochromatic images(4.90 ± 0.35 vs 4.53 ± 1.15,P < 0.05),and calcium base images were superior to lipid base images(4.91 ± 0.43 vs 4.77 ± 0.63,P < 0.05),but there was no statisticallysignificant difference between 40 ke V monochromatic images and calcium base images(4.90 ± 0.35 vs 4.91 ± 0.43,P > 0.05). In 217 gallbladder stone patients,there were 21,3,28,5 and 12 negative stone cases in polychromatic images,40 ke V images,140 ke V images,calcium base images and lipid base images,respectively,and the differences among the five groups were statistically significant(P < 0.05).CONCLUSION:Monochromatic images展开更多
基金Foundation item： National Natural Science Foundation of China （60879024）
文摘Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitions becomes popular as an alternative to the traditional federated architecture. This study investigates the problem of designing hierarchical scheduling for IMA systems. The proposed scheduler model enables strong temporal partitioning, so that multiple hard real-time applications can be easily integrated into an uniprocessor platform. This paper derives the mathematic relationships among parti- tion cycle, partition capacity and schedulability under the real-time condition, and then proposes an algorithm for optimizing partition parameters. Real-time tasks with arbitrary deadlines are considered for generality. To further improve the basic algo- rithm and reduce the energy consumption for embedded systems in aircraft, a power optimization approach is also proposed by exploiting the slack time. Experimental results show that the designed system can guarantee the hard real-time requirement and reduce the power consumption by at least 14%.
文摘AIM:To evaluate the detectability of gallbladder stones by dual-energy spectral computed tomography(CT) imaging.METHODS:Totally 217 patients with surgically confirmed gallbladder stones were retrospectively analyzed who underwent single-source dual-energy CT scanning from August 2011 to December 2013. Polychromatic images were acquired. And post-processing software was used to reconstruct monochromatic(40 ke V and 140 ke V) images,and calcium-lipid pair-wise base substance was selected to acquire calcium base images and lipid base images. The above 5 groups of images were evaluated by two radiologists separately with 10-year experience in CT image reading. In the 5 groups of images,the cases in the positive group and negative group were counted and then the detection rate was calculated. The inter-observer agreement on the scoring results was analyzed by Kappa test,and the scoring results were analyzed by Wilcoxon test,with P < 0.05 indicating that the difference was statistically significant. The stone detection results of the 5 groups of images were analyzed by χ2 test.RESULTS:There was good inter-observer agreement(k = 0.772). In 217 patients with gallbladder stones,there was a statistically significant difference in stone visualization between spectral images(40 ke V,140 ke V,calcium base and lipid base images) and polychromatic images(P < 0.05). 40 ke V monochromatic images were better than 140 ke V monochromatic images(4.90 ± 0.35 vs 4.53 ± 1.15,P < 0.05),and calcium base images were superior to lipid base images(4.91 ± 0.43 vs 4.77 ± 0.63,P < 0.05),but there was no statisticallysignificant difference between 40 ke V monochromatic images and calcium base images(4.90 ± 0.35 vs 4.91 ± 0.43,P > 0.05). In 217 gallbladder stone patients,there were 21,3,28,5 and 12 negative stone cases in polychromatic images,40 ke V images,140 ke V images,calcium base images and lipid base images,respectively,and the differences among the five groups were statistically significant(P < 0.05).CONCLUSION:Monochromatic images
