A very fast simulated annealing（VFSA） global optimization is used to interpret residual gravity anomaly.Since,VFSA optimization yields a large number of best-fitted models in a vast model space;the nature of uncerta...A very fast simulated annealing（VFSA） global optimization is used to interpret residual gravity anomaly.Since,VFSA optimization yields a large number of best-fitted models in a vast model space;the nature of uncertainty in the interpretation is also examined simultaneously in the present study.The results of VFSA optimization reveal that various parameters show a number of equivalent solutions when shape of the target body is not known and shape factor ＇q＇ is also optimized together with other model parameters.The study reveals that amplitude coefficient k is strongly dependent on shape factor.This shows that there is a multi-model type uncertainty between these two model parameters derived from the analysis of cross-plots.However,the appraised values of shape factor from various VFSA runs clearly indicate whether the subsurface structure is sphere,horizontal or vertical cylinder type structure.Accordingly,the exact shape factor（1.5 for sphere,1.0 for horizontal cylinder and 0.5 for vertical cylinder）is fixed and optimization process is repeated.After fixing the shape factor,analysis of uncertainty and cross-plots shows a well-defined uni-model characteristic.The mean model computed after fixing the shape factor gives the utmost consistent results.Inversion of noise-free and noisy synthetic data as well as field data demonstrates the efficacy of the approach.展开更多
This paper argues that“the fear of having two sons”is a gender structure phenom-enon that causes anxiety for some Chinese families.To prove the existence of such a fear in some families,this paper considers three as...This paper argues that“the fear of having two sons”is a gender structure phenom-enon that causes anxiety for some Chinese families.To prove the existence of such a fear in some families,this paper considers three aspects:the ideal gender structure of children,women’s childbearing plan for second children and their actual child-bearing behavior.Data for nine provinces is taken from the China Fertility Survey of 2017.This paper finds that:(1)except for having no children,2 sons and 0 daughters is the most undesired gender structure;(2)among those who expect 1 son and 1 daughter,women whose first child is a son are less likely to plan to have a second child than those whose first child is a daughter;(3)among those who expect 1 son and 1 daughter,women with a son as the first child are less likely to have a second child than those with a daughter.These findings prove that,at present,the phenom-enon of the fear of having two sons does exist in some Chinese families.Finally,this paper summarizes how the attitudes of Chinese families towards having sons have changed since the 1950s from“a hope for having many sons”to“a desire for at least one son”and finally to“the fear of having two sons.”The paper also discusses the significance of the fear of having two sons phenomenon in terms of improving the proximate determinants of low fertility model.展开更多
文摘A very fast simulated annealing（VFSA） global optimization is used to interpret residual gravity anomaly.Since,VFSA optimization yields a large number of best-fitted models in a vast model space;the nature of uncertainty in the interpretation is also examined simultaneously in the present study.The results of VFSA optimization reveal that various parameters show a number of equivalent solutions when shape of the target body is not known and shape factor ＇q＇ is also optimized together with other model parameters.The study reveals that amplitude coefficient k is strongly dependent on shape factor.This shows that there is a multi-model type uncertainty between these two model parameters derived from the analysis of cross-plots.However,the appraised values of shape factor from various VFSA runs clearly indicate whether the subsurface structure is sphere,horizontal or vertical cylinder type structure.Accordingly,the exact shape factor（1.5 for sphere,1.0 for horizontal cylinder and 0.5 for vertical cylinder）is fixed and optimization process is repeated.After fixing the shape factor,analysis of uncertainty and cross-plots shows a well-defined uni-model characteristic.The mean model computed after fixing the shape factor gives the utmost consistent results.Inversion of noise-free and noisy synthetic data as well as field data demonstrates the efficacy of the approach.
文摘This paper argues that“the fear of having two sons”is a gender structure phenom-enon that causes anxiety for some Chinese families.To prove the existence of such a fear in some families,this paper considers three aspects:the ideal gender structure of children,women’s childbearing plan for second children and their actual child-bearing behavior.Data for nine provinces is taken from the China Fertility Survey of 2017.This paper finds that:(1)except for having no children,2 sons and 0 daughters is the most undesired gender structure;(2)among those who expect 1 son and 1 daughter,women whose first child is a son are less likely to plan to have a second child than those whose first child is a daughter;(3)among those who expect 1 son and 1 daughter,women with a son as the first child are less likely to have a second child than those with a daughter.These findings prove that,at present,the phenom-enon of the fear of having two sons does exist in some Chinese families.Finally,this paper summarizes how the attitudes of Chinese families towards having sons have changed since the 1950s from“a hope for having many sons”to“a desire for at least one son”and finally to“the fear of having two sons.”The paper also discusses the significance of the fear of having two sons phenomenon in terms of improving the proximate determinants of low fertility model.
