Back-propagation artificial neural network (BPANN) is used in ball backward spinning in order to form thin-walled tubular parts with longitudinal inner ribs. By selecting the process parameters which have a great infl...Back-propagation artificial neural network (BPANN) is used in ball backward spinning in order to form thin-walled tubular parts with longitudinal inner ribs. By selecting the process parameters which have a great influence on the height of inner ribs as well as fish scale on the surface of the spun part, a BPANN of 3-8-1 structure is established for predicting the height of inner rib and recognizing the fish scale defect. Experiments data have proved that the average relative error between the measured value and the predicted value of the height of inner rib is not more than 5%. It is evident that BPANN can not only predict the height of inner ribs of the spun part accurately, but recognize and prevent the occurrence of the quality defect of fish scale successfully, and combining BPANN with the ball backward spinning is essential to obtain the desired spun part.展开更多
To investigate the mortality of malignant tumor in female workers exposed to chrysotile asbestos.Methods A retrospective cohort study of female workers was conducted,who had been engaged in the manual spinning of chry...To investigate the mortality of malignant tumor in female workers exposed to chrysotile asbestos.Methods A retrospective cohort study of female workers was conducted,who had been engaged in the manual spinning of chrysotile in family with more than one year between January 1,1960 and December 31,1980.Resuits A total of 144 persons were found to be dead from cancer.Among them the most frequent was lung cancer(74), and the second liver cancer(27),and the third stomach cancer(18).Standardized mortality ratio(SMR)from total malingnant tumor and lung cancer were 1.16(P<0.05)and 4.17(P<0.01),respectively based on the control population of the same region.Conclusion A significant excess death from lung cancer was found among female workers who had been exposed to chrysotile.展开更多
文摘Back-propagation artificial neural network (BPANN) is used in ball backward spinning in order to form thin-walled tubular parts with longitudinal inner ribs. By selecting the process parameters which have a great influence on the height of inner ribs as well as fish scale on the surface of the spun part, a BPANN of 3-8-1 structure is established for predicting the height of inner rib and recognizing the fish scale defect. Experiments data have proved that the average relative error between the measured value and the predicted value of the height of inner rib is not more than 5%. It is evident that BPANN can not only predict the height of inner ribs of the spun part accurately, but recognize and prevent the occurrence of the quality defect of fish scale successfully, and combining BPANN with the ball backward spinning is essential to obtain the desired spun part.
文摘To investigate the mortality of malignant tumor in female workers exposed to chrysotile asbestos.Methods A retrospective cohort study of female workers was conducted,who had been engaged in the manual spinning of chrysotile in family with more than one year between January 1,1960 and December 31,1980.Resuits A total of 144 persons were found to be dead from cancer.Among them the most frequent was lung cancer(74), and the second liver cancer(27),and the third stomach cancer(18).Standardized mortality ratio(SMR)from total malingnant tumor and lung cancer were 1.16(P<0.05)and 4.17(P<0.01),respectively based on the control population of the same region.Conclusion A significant excess death from lung cancer was found among female workers who had been exposed to chrysotile.
