We introduced a decision tree method called Random Forests for multiwavelength data classification. The data were adopted from different databases, including the Sloan Digital Sky Survey （SDSS） Data Release five, US...We introduced a decision tree method called Random Forests for multiwavelength data classification. The data were adopted from different databases, including the Sloan Digital Sky Survey （SDSS） Data Release five, USNO, FIRST and ROSAT. We then studied the discrimination of quasars from stars and the classification of quasars, stars and galaxies with the sample from optical and radio bands and with that from optical and X-ray bands. Moreover, feature selection and feature weighting based on Random Forests were investigated. The performances based on different input patterns were compared. The experimental results show that the random forest method is an effective method for astronomical object classification and can be applied to other classification problems faced in astronomy. In addition, Random Forests will show its superiorities due to its own merits, e.g. classification, feature selection, feature weighting as well as outlier detection.展开更多
Objectives To investigate the causes, theraputic and preventive methods of com- plications associated with transcatheter occlusion of at- rial septal defect ( ASD) using the Amplatzer septal oc- cluder (ASO) in childr...Objectives To investigate the causes, theraputic and preventive methods of com- plications associated with transcatheter occlusion of at- rial septal defect ( ASD) using the Amplatzer septal oc- cluder (ASO) in children. Methods 289 cases un- derwent transcatheter closure of ASD with ASO. Com- plications occurred in 9 cases. The complications in procedure included systemic circulatory systemic air embolism in 2, pulmonary air embolism in 1, pericar- dial tamponade in 1, ASO malposition requiring emer- gency surgical removal in 1, transient atrial extrasysto- les in 1 and sizing balloon rupture in 1 case. 2 cases with postoperative complications were found in the fol- low-up studies. These included perforation of mitral valve and ASO partially dislodged. In this study, 5 children with intraoperative complication received e- mergency therapy including surgical intervention, and others needed only follow-up, as the complications were transient or asymptomatic. Results There were no children death in this study. The 5 cases who re- ceived treatment were completely healing, and the oth- ers with intra - procedure complications were also had no sequela existed. Cases with mitral valve and ASO partially dislodged were still in follow-up studies, as the 2 patients having no symptoms. Conclutions Air embolism were occurred easily in atrial septal defect cases who received ASO therapy. Complications mainly caused by inappropriate operative procedure and some complications needed emergency treatments. Follow-up studies were important to cases with transcatheter oc- clusion therapy.展开更多
A multisymplectic Fourier pseudo-spectral scheme, which exactly preserves the discrete multisym- plectic conservation law, is presented to solve the Klein-Gordon-SchrSdinger equations. The scheme is of spectral accura...A multisymplectic Fourier pseudo-spectral scheme, which exactly preserves the discrete multisym- plectic conservation law, is presented to solve the Klein-Gordon-SchrSdinger equations. The scheme is of spectral accuracy in space and of second order in time. The scheme preserves the discrete multisymplectic conservation law and the charge conservation law. Moreover, the residuals of some other conservation laws are derived for the geometric numerical integrator. Extensive numerical simulations illustrate the numerical behavior of the multisymplectic scheme, and demonstrate the correctness of the theoretical analysis.展开更多
基金Supported by the National Natural Science Foundation of ChinaThis paper is funded by the National Natural Science Foundation of China under grant under GrantNos. 10473013, 90412016 and 10778724 by the 863 project under Grant No. 2006AA01A120
文摘We introduced a decision tree method called Random Forests for multiwavelength data classification. The data were adopted from different databases, including the Sloan Digital Sky Survey （SDSS） Data Release five, USNO, FIRST and ROSAT. We then studied the discrimination of quasars from stars and the classification of quasars, stars and galaxies with the sample from optical and radio bands and with that from optical and X-ray bands. Moreover, feature selection and feature weighting based on Random Forests were investigated. The performances based on different input patterns were compared. The experimental results show that the random forest method is an effective method for astronomical object classification and can be applied to other classification problems faced in astronomy. In addition, Random Forests will show its superiorities due to its own merits, e.g. classification, feature selection, feature weighting as well as outlier detection.
文摘Objectives To investigate the causes, theraputic and preventive methods of com- plications associated with transcatheter occlusion of at- rial septal defect ( ASD) using the Amplatzer septal oc- cluder (ASO) in children. Methods 289 cases un- derwent transcatheter closure of ASD with ASO. Com- plications occurred in 9 cases. The complications in procedure included systemic circulatory systemic air embolism in 2, pulmonary air embolism in 1, pericar- dial tamponade in 1, ASO malposition requiring emer- gency surgical removal in 1, transient atrial extrasysto- les in 1 and sizing balloon rupture in 1 case. 2 cases with postoperative complications were found in the fol- low-up studies. These included perforation of mitral valve and ASO partially dislodged. In this study, 5 children with intraoperative complication received e- mergency therapy including surgical intervention, and others needed only follow-up, as the complications were transient or asymptomatic. Results There were no children death in this study. The 5 cases who re- ceived treatment were completely healing, and the oth- ers with intra - procedure complications were also had no sequela existed. Cases with mitral valve and ASO partially dislodged were still in follow-up studies, as the 2 patients having no symptoms. Conclutions Air embolism were occurred easily in atrial septal defect cases who received ASO therapy. Complications mainly caused by inappropriate operative procedure and some complications needed emergency treatments. Follow-up studies were important to cases with transcatheter oc- clusion therapy.
基金supported by National Natural Science Foundation of China(Grant Nos.10901074,11271171,91130003,11001009 and 11101399)the Province Natural Science Foundation of Jiangxi(Grant No. 20114BAB201011)+2 种基金the Foundation of Department of Education of Jiangxi Province(Grant No.GJJ12174)the State Key Laboratory of Scientific and Engineering Computing,CASsupported by the Youth Growing Foundation of Jiangxi Normal University in 2010
文摘A multisymplectic Fourier pseudo-spectral scheme, which exactly preserves the discrete multisym- plectic conservation law, is presented to solve the Klein-Gordon-SchrSdinger equations. The scheme is of spectral accuracy in space and of second order in time. The scheme preserves the discrete multisymplectic conservation law and the charge conservation law. Moreover, the residuals of some other conservation laws are derived for the geometric numerical integrator. Extensive numerical simulations illustrate the numerical behavior of the multisymplectic scheme, and demonstrate the correctness of the theoretical analysis.
