We introduce the general AC( atlribure certificate), the role specificationAC and the rolt assignment AC We discuss the rolt-based PMI(Privilege Management Infrastructure)architecture. The role-based PMT(Public-Kty In...We introduce the general AC( atlribure certificate), the role specificationAC and the rolt assignment AC We discuss the rolt-based PMI(Privilege Management Infrastructure)architecture. The role-based PMT(Public-Kty In-frastructure) secure model forE-govcrnment isresearehed by combining the role-bastd PMI with PKI architeclure (Public Key Infrastructure). Themodel has advantages of flexibility, convenience, less storage space and less network consumptionetc. We are going to ust iht secure modelin the E-govern-ment system.展开更多
Beef consumption in China has increased substantially from 5.0 million tons in 2000 to 7.7 million tons in 2019 thanks to rapid income growth,but still remains low compared to pork and poultry consumption.Improving th...Beef consumption in China has increased substantially from 5.0 million tons in 2000 to 7.7 million tons in 2019 thanks to rapid income growth,but still remains low compared to pork and poultry consumption.Improving the understanding about the impacts of household income on beef consumption in China is necessary to forecast future beef demand and inform the domestic beef industry,especially in the context of unprecedented expansion of middle income class in China.Based on survey data of 32878 urban households collected by the National Bureau of Statistics of China,we employed the inverse hyperbolic sine(IHS)double-hurdle model to estimate income elasticities of beef demand across different income groups and simulated possible trends of future beef consumption of Chinese urban residents.The empirical results showed that the unconditional income elasticities of beef consumption at home vary between 0.169 for the lowincome group and 0.671 for the high-income group.The simulated results indicated that beef consumption is expected to increase by 12.0 to 38.8%in 10 years and by 18.6 to 70.5%in 15 years under distinct income growth scenarios.Our findings provide practical insights for policy makers and other stakeholders about future beef demand,such as potential opportunities embedded in rising beef demand for domestic producers and world beef exporters as well as the urgency of improving the supply chain resilience of beef in China.展开更多
文摘We introduce the general AC( atlribure certificate), the role specificationAC and the rolt assignment AC We discuss the rolt-based PMI(Privilege Management Infrastructure)architecture. The role-based PMT(Public-Kty In-frastructure) secure model forE-govcrnment isresearehed by combining the role-bastd PMI with PKI architeclure (Public Key Infrastructure). Themodel has advantages of flexibility, convenience, less storage space and less network consumptionetc. We are going to ust iht secure modelin the E-govern-ment system.
基金the National Natural Science Foundation of China(71473251)。
文摘Beef consumption in China has increased substantially from 5.0 million tons in 2000 to 7.7 million tons in 2019 thanks to rapid income growth,but still remains low compared to pork and poultry consumption.Improving the understanding about the impacts of household income on beef consumption in China is necessary to forecast future beef demand and inform the domestic beef industry,especially in the context of unprecedented expansion of middle income class in China.Based on survey data of 32878 urban households collected by the National Bureau of Statistics of China,we employed the inverse hyperbolic sine(IHS)double-hurdle model to estimate income elasticities of beef demand across different income groups and simulated possible trends of future beef consumption of Chinese urban residents.The empirical results showed that the unconditional income elasticities of beef consumption at home vary between 0.169 for the lowincome group and 0.671 for the high-income group.The simulated results indicated that beef consumption is expected to increase by 12.0 to 38.8%in 10 years and by 18.6 to 70.5%in 15 years under distinct income growth scenarios.Our findings provide practical insights for policy makers and other stakeholders about future beef demand,such as potential opportunities embedded in rising beef demand for domestic producers and world beef exporters as well as the urgency of improving the supply chain resilience of beef in China.
