The similarity transformation model between different coordinate systems is not accurate enough to describe the discrepancy of them.Therefore,the coordinate transformation from the coordinate frame with poor accuracy ...The similarity transformation model between different coordinate systems is not accurate enough to describe the discrepancy of them.Therefore,the coordinate transformation from the coordinate frame with poor accuracy to that with high accuracy cannot guarantee a high precision of transformation.In this paper,a combined method of similarity transformation and regressive approximating is presented.The local error accumulation and distortion are taken into consideration and the precision of coordinate system is improved by using the recommended method展开更多
Objective： To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods： Six anthropometric parameters were measured in 50 m...Objective： To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods： Six anthropometric parameters were measured in 50 male and 50 female medical students using a metallic scale： medial knee joint line to ankle joint line （K-A）, medial knee joint line to medial malleolus （K-MM）, tibial tuberosity to ankle joint （TT-A）, tibial tuberosity to medial malleolus （TT- MM）, olecranon to 5th metacarpal head （O-MH） and body height （BH）. Nail size predicted based upon Tr-MM measurement was chosen as ideal nail size. A constant was derived for each of the six anthropometric parameters which was either added or subtracted to each measurement to derive nail size. A regression equation was applied to BH measurements. Nail sizes calculated were compared with that obtained from TI＇-MM measurement and accuracy was evaluated. Accuracy of O-MH and BH regression equations recommended by other authors were calculated in our data. Results： Adding 11 mm to Tr-A distance had highest accuracy （81%） and correlation （0.966） in predicting nails correctly. Subtracting 33 mm from K-MM measurement and 25 mm from K-A distance derived accurate sizes in 69% and 76% respectively. Adding 6 mm to O-MH distance had a poor accuracy of 51%. Nail size prediction based upon body height regression equation derived correct nail sizes in only 34% of the cases. Regression equation analysis by other authors based on O-MH and BH distances yielded correct sizes in 11% and 5% of the cases respectively. Conclusion： TT-A, K-A and K-MM measurements can be used simultaneously to increase accuracy of nail size prediction. This method would be helpful in determining nail size preoperatively especially when one anatomic landmark is difficult to palpate.展开更多
Some insights and analysis are presented concerning the monitoring model of the VLBI(Very Long Baseline Interferometry) antenna,settings of parameters and selection of constraints to the observation equation,which are...Some insights and analysis are presented concerning the monitoring model of the VLBI(Very Long Baseline Interferometry) antenna,settings of parameters and selection of constraints to the observation equation,which are verified via data simulation analysis to be reasonable and effective.The effects of the number of targets and antenna orientations,the precision of target positioning observations,the observation outliers detection and deletion on the determination precision of antenna parameters are also analyzed,and some preliminary conclusions are given.展开更多
文摘The similarity transformation model between different coordinate systems is not accurate enough to describe the discrepancy of them.Therefore,the coordinate transformation from the coordinate frame with poor accuracy to that with high accuracy cannot guarantee a high precision of transformation.In this paper,a combined method of similarity transformation and regressive approximating is presented.The local error accumulation and distortion are taken into consideration and the precision of coordinate system is improved by using the recommended method
文摘Objective： To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods： Six anthropometric parameters were measured in 50 male and 50 female medical students using a metallic scale： medial knee joint line to ankle joint line （K-A）, medial knee joint line to medial malleolus （K-MM）, tibial tuberosity to ankle joint （TT-A）, tibial tuberosity to medial malleolus （TT- MM）, olecranon to 5th metacarpal head （O-MH） and body height （BH）. Nail size predicted based upon Tr-MM measurement was chosen as ideal nail size. A constant was derived for each of the six anthropometric parameters which was either added or subtracted to each measurement to derive nail size. A regression equation was applied to BH measurements. Nail sizes calculated were compared with that obtained from TI＇-MM measurement and accuracy was evaluated. Accuracy of O-MH and BH regression equations recommended by other authors were calculated in our data. Results： Adding 11 mm to Tr-A distance had highest accuracy （81%） and correlation （0.966） in predicting nails correctly. Subtracting 33 mm from K-MM measurement and 25 mm from K-A distance derived accurate sizes in 69% and 76% respectively. Adding 6 mm to O-MH distance had a poor accuracy of 51%. Nail size prediction based upon body height regression equation derived correct nail sizes in only 34% of the cases. Regression equation analysis by other authors based on O-MH and BH distances yielded correct sizes in 11% and 5% of the cases respectively. Conclusion： TT-A, K-A and K-MM measurements can be used simultaneously to increase accuracy of nail size prediction. This method would be helpful in determining nail size preoperatively especially when one anatomic landmark is difficult to palpate.
基金supported by the National Natural Sciences Foundation of China(Grant Nos.11178024 and 10973030)the Lunar Exploration of China(Chang’E 2 and 3)+1 种基金the Committee of Sciences and Technology of Shanghai(Grant No.06DZ22101)the National High Technology Research and Development Program of China(Grant No.2012AA121603)
文摘Some insights and analysis are presented concerning the monitoring model of the VLBI(Very Long Baseline Interferometry) antenna,settings of parameters and selection of constraints to the observation equation,which are verified via data simulation analysis to be reasonable and effective.The effects of the number of targets and antenna orientations,the precision of target positioning observations,the observation outliers detection and deletion on the determination precision of antenna parameters are also analyzed,and some preliminary conclusions are given.
