Rice production is crucial for food security in China,and its relationship with rural labor migration has been studied extensively.Labor migration in rural China has taken new forms in recent years.There has been a di...Rice production is crucial for food security in China,and its relationship with rural labor migration has been studied extensively.Labor migration in rural China has taken new forms in recent years.There has been a discernible trend wherein adult children have started migrating to cities while their elderly parents return to villages to re-engage in on-farm work.The phenomenon has notably shaped the intergenerational division of labor(IDL)within households.However,it remains to be seen how farmers adjust their rice production systems in response to the IDL.The age of 60 years for employment injury insurance is the eligibility threshold for off-farm employment and is used to obtain a source of exogenous variation in the IDL.Based on a representative household survey of 1,752 rice farmers in the Hubei Province of Central China,our fuzzy regression discontinuity analysis reveals that farmers in IDL households are more likely to adopt ratoon rice(RR)than single cropping rice(SR)or double cropping rice(DR).The effect of the IDL varies under different levels of operational scales and specialized agricultural service availability.Further analysis suggests that farmers’arrangements are associated with two potential mechanisms of downward intergenerational transfer.Monetary transfer for urban housing purchases increases RR in IDL households,and time transfer for intergenerational childcare significantly promotes SR in IDL households.This study enhances the understanding of the relationship between rural labor migration and rice production in China,providing a reference for adjusting rice production systems to ensure food security.展开更多
It is difficult for the double suppression division algorithm of bee colony to solve the spatio-temporal coupling or have higher dimensional attributes and undertake sudden tasks.Using the idea of clustering,after clu...It is difficult for the double suppression division algorithm of bee colony to solve the spatio-temporal coupling or have higher dimensional attributes and undertake sudden tasks.Using the idea of clustering,after clustering tasks according to spatio-temporal attributes,the clustered groups are linked into task sub-chains according to similarity.Then,based on the correlation between clusters,the child chains are connected to form a task chain.Therefore,the limitation is solved that the task chain in the bee colony algorithm can only be connected according to one dimension.When a sudden task occurs,a method of inserting a small number of tasks into the original task chain and a task chain reconstruction method are designed according to the relative relationship between the number of sudden tasks and the number of remaining tasks.Through the above improvements,the algorithm can be used to process tasks with spatio-temporal coupling and burst tasks.In order to reflect the efficiency and applicability of the algorithm,a task allocation model for the unmanned aerial vehicle(UAV)group is constructed,and a one-to-one correspondence between the improved bee colony double suppression division algorithm and each attribute in the UAV group is proposed.Task assignment has been constructed.The study uses the self-adjusting characteristics of the bee colony to achieve task allocation.Simulation verification and algorithm comparison show that the algorithm has stronger planning advantages and algorithm performance.展开更多
Based on a refined "non-competitive input-output model," this paper proposes a new framework for analyzing the status of a country's high-tech industries in the international division of labor, i.e. calculates the ...Based on a refined "non-competitive input-output model," this paper proposes a new framework for analyzing the status of a country's high-tech industries in the international division of labor, i.e. calculates the index of" weighted value-added productivity " by compiling non-competitive input-output tables which distinguish high-tech industries from traditional industries. The new method effectively avoids "statistical illusion" which stems from a biased focus on gross exports under intra-product specialization. The empirical study shows that since 1995, the status of China's high-tech industries has grown quickly as a result of enhanced labor productivity, but still lags behind those of major developed countries. In addition, the study also suggests that the status of China's high-tech industries has been over-estimated using the traditional gross export statistical method.展开更多
This paper has identified two models of intra-product international division of labor:the model of passive inclusion and the model of proactive participation.Their difference is essentially whether participation in in...This paper has identified two models of intra-product international division of labor:the model of passive inclusion and the model of proactive participation.Their difference is essentially whether participation in international division of labor is dominated by multinational firms or by local firms.At the level of representative sectors,some characteristic variables of participation in international division of labor demonstrate significant industry differences.Models of division of labor affect technology progress.According to the empirical analysis result at the micro-level of four sectors,no matter for export or the contribution of learning by doing to corporate technology progress,the model of proactive participation is superior to the model of passive inclusion;under the model of passive inclusion,the technology spillover effect of import is smaller than "learning by doing " effect;under the model of proactive participation,technology spillover effect is over two times the "learning by doing" effect.展开更多
Background: The objective of this study was to analyze how involvement in paid and unpaid work and perceived labor-related stress are related to the well-being of married or cohabiting men and women in Europe. Methods...Background: The objective of this study was to analyze how involvement in paid and unpaid work and perceived labor-related stress are related to the well-being of married or cohabiting men and women in Europe. Methods: Data from the European Social Survey round two has been used. The sample consists of 5800 women and 6952 men, aged between 18-65 years. Exposure variables were divided into labor involvement, time spent on paid and unpaid work, and labor-related stress. Multiple logistic regressions with 95 % confidence interval were used. Results: Women spent more hours on housework than men did, but fewer hours on paid work. Women tended to perceive higher degrees of housework-related stress than men did. Furthermore, women who experienced houseworkrelated stress tended to have higher odds of reporting a low level of perceived well-being than men, while men had higher odds of reporting a low level of perceived well-being when they experienced work/family conflicts. Conclusion: For both men and women, the perceptions of labor involvement are of more importance for the well-being than the actual time spent on paid and unpaid work. This implies that, when studying the relationship between labor involvement and well-being, perceived stress should be considered.展开更多
基金supported by the National Natural Science Foundation of China(42207529)the China Postdoctoral Science Foundation(2022M721289).
文摘Rice production is crucial for food security in China,and its relationship with rural labor migration has been studied extensively.Labor migration in rural China has taken new forms in recent years.There has been a discernible trend wherein adult children have started migrating to cities while their elderly parents return to villages to re-engage in on-farm work.The phenomenon has notably shaped the intergenerational division of labor(IDL)within households.However,it remains to be seen how farmers adjust their rice production systems in response to the IDL.The age of 60 years for employment injury insurance is the eligibility threshold for off-farm employment and is used to obtain a source of exogenous variation in the IDL.Based on a representative household survey of 1,752 rice farmers in the Hubei Province of Central China,our fuzzy regression discontinuity analysis reveals that farmers in IDL households are more likely to adopt ratoon rice(RR)than single cropping rice(SR)or double cropping rice(DR).The effect of the IDL varies under different levels of operational scales and specialized agricultural service availability.Further analysis suggests that farmers’arrangements are associated with two potential mechanisms of downward intergenerational transfer.Monetary transfer for urban housing purchases increases RR in IDL households,and time transfer for intergenerational childcare significantly promotes SR in IDL households.This study enhances the understanding of the relationship between rural labor migration and rice production in China,providing a reference for adjusting rice production systems to ensure food security.
基金This work was supported by the National Natural Science and Technology Innovation 2030 Major Project of Ministry of Science and Technology of China(2018AAA0101200)the National Natural Science Foundation of China(61502522,61502534)+4 种基金the Equipment Pre-Research Field Fund(JZX7Y20190253036101)the Equipment Pre-Research Ministry of Education Joint Fund(6141A02033703)Shaanxi Provincial Natural Science Foundation(2020JQ-493)the Military Science Project of the National Social Science Fund(WJ2019-SKJJ-C-092)the Theoretical Research Foundation of Armed Police Engineering University(WJY202148).
文摘It is difficult for the double suppression division algorithm of bee colony to solve the spatio-temporal coupling or have higher dimensional attributes and undertake sudden tasks.Using the idea of clustering,after clustering tasks according to spatio-temporal attributes,the clustered groups are linked into task sub-chains according to similarity.Then,based on the correlation between clusters,the child chains are connected to form a task chain.Therefore,the limitation is solved that the task chain in the bee colony algorithm can only be connected according to one dimension.When a sudden task occurs,a method of inserting a small number of tasks into the original task chain and a task chain reconstruction method are designed according to the relative relationship between the number of sudden tasks and the number of remaining tasks.Through the above improvements,the algorithm can be used to process tasks with spatio-temporal coupling and burst tasks.In order to reflect the efficiency and applicability of the algorithm,a task allocation model for the unmanned aerial vehicle(UAV)group is constructed,and a one-to-one correspondence between the improved bee colony double suppression division algorithm and each attribute in the UAV group is proposed.Task assignment has been constructed.The study uses the self-adjusting characteristics of the bee colony to achieve task allocation.Simulation verification and algorithm comparison show that the algorithm has stronger planning advantages and algorithm performance.
文摘Based on a refined "non-competitive input-output model," this paper proposes a new framework for analyzing the status of a country's high-tech industries in the international division of labor, i.e. calculates the index of" weighted value-added productivity " by compiling non-competitive input-output tables which distinguish high-tech industries from traditional industries. The new method effectively avoids "statistical illusion" which stems from a biased focus on gross exports under intra-product specialization. The empirical study shows that since 1995, the status of China's high-tech industries has grown quickly as a result of enhanced labor productivity, but still lags behind those of major developed countries. In addition, the study also suggests that the status of China's high-tech industries has been over-estimated using the traditional gross export statistical method.
文摘This paper has identified two models of intra-product international division of labor:the model of passive inclusion and the model of proactive participation.Their difference is essentially whether participation in international division of labor is dominated by multinational firms or by local firms.At the level of representative sectors,some characteristic variables of participation in international division of labor demonstrate significant industry differences.Models of division of labor affect technology progress.According to the empirical analysis result at the micro-level of four sectors,no matter for export or the contribution of learning by doing to corporate technology progress,the model of proactive participation is superior to the model of passive inclusion;under the model of passive inclusion,the technology spillover effect of import is smaller than "learning by doing " effect;under the model of proactive participation,technology spillover effect is over two times the "learning by doing" effect.
文摘Background: The objective of this study was to analyze how involvement in paid and unpaid work and perceived labor-related stress are related to the well-being of married or cohabiting men and women in Europe. Methods: Data from the European Social Survey round two has been used. The sample consists of 5800 women and 6952 men, aged between 18-65 years. Exposure variables were divided into labor involvement, time spent on paid and unpaid work, and labor-related stress. Multiple logistic regressions with 95 % confidence interval were used. Results: Women spent more hours on housework than men did, but fewer hours on paid work. Women tended to perceive higher degrees of housework-related stress than men did. Furthermore, women who experienced houseworkrelated stress tended to have higher odds of reporting a low level of perceived well-being than men, while men had higher odds of reporting a low level of perceived well-being when they experienced work/family conflicts. Conclusion: For both men and women, the perceptions of labor involvement are of more importance for the well-being than the actual time spent on paid and unpaid work. This implies that, when studying the relationship between labor involvement and well-being, perceived stress should be considered.