In this research, the result of the cloud seeding over Yazd province during three months of February, March and April in 1999 has been evaluated using the historical regression method. Hereupon, the rain-gages in Yazd...In this research, the result of the cloud seeding over Yazd province during three months of February, March and April in 1999 has been evaluated using the historical regression method. Hereupon, the rain-gages in Yazd province as the target stations and the rain-gages of the neighboring provinces as the control stations have been selected. The rainfall averages for the three aforementioned months through 25 years (1973-1997) in all control and target stations have been calculated. In the next step, the correlations between the rainfalls of control and target stations have been estimated about 75%, which indicates a good consistency in order to use the historical regression. Then, through the obtained liner correlation equation between the control and target stations the precipitation amount for February, March and April in 1999, over the target region (Yazd province) was estimated about 27.57 mm, whiles the observed amount was 34.23 mm. In fact the precipitation increasing around 19.5% over Yazd province confirmed the success of this cloud seeding project.展开更多
Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial pane...Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.展开更多
Three indexes including forest pest occurrence area,control area and input fund of 31 provinces from 2003 to 2014 were selected from Forestry Statistical Yearbook,to establish dynamic interaction index evaluation syst...Three indexes including forest pest occurrence area,control area and input fund of 31 provinces from 2003 to 2014 were selected from Forestry Statistical Yearbook,to establish dynamic interaction index evaluation system with clustering robust regression model and Stata 13. 0 software. Total forest pest control efficiency in China was determined according to the computing result of entropy method. Suggestions such as improving forest pest control efficiency,increasing service efficiency and input amount of forest pest control input funds were put forward. It will provide empirical basis for target management evaluation of forest pest control work and accountability system.展开更多
分析了系统温度对机抖激光陀螺捷联惯性导航系统的影响因素,介绍了降低和补偿捷联系统温度误差的4种方法。通过重复性温度实验,利用逐步回归法分析了激光陀螺零偏与温度的关系;通过多项式拟合,分别得到了加速度计的零偏、标度因子和IF...分析了系统温度对机抖激光陀螺捷联惯性导航系统的影响因素,介绍了降低和补偿捷联系统温度误差的4种方法。通过重复性温度实验,利用逐步回归法分析了激光陀螺零偏与温度的关系;通过多项式拟合,分别得到了加速度计的零偏、标度因子和IF转换电路的温度补偿模型,并在捷联系统中得到应用。对其中的两种方法进行了实验研究和导航测试,并对两种方法的补偿效果进行了对比。结果表明:通过温度实验得到惯性器件的温度补偿模型对其温度误差进行实时补偿是捷联系统最理想的补偿方法。补偿后系统定位测试1 h的圆概率误差(CEP)优于0.3 n mile/h,达到国内先进水平。展开更多
文摘In this research, the result of the cloud seeding over Yazd province during three months of February, March and April in 1999 has been evaluated using the historical regression method. Hereupon, the rain-gages in Yazd province as the target stations and the rain-gages of the neighboring provinces as the control stations have been selected. The rainfall averages for the three aforementioned months through 25 years (1973-1997) in all control and target stations have been calculated. In the next step, the correlations between the rainfalls of control and target stations have been estimated about 75%, which indicates a good consistency in order to use the historical regression. Then, through the obtained liner correlation equation between the control and target stations the precipitation amount for February, March and April in 1999, over the target region (Yazd province) was estimated about 27.57 mm, whiles the observed amount was 34.23 mm. In fact the precipitation increasing around 19.5% over Yazd province confirmed the success of this cloud seeding project.
文摘Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.
基金Supported by Analysis of Forest Pest Cost Responsibility Investigation System(2017-R04)Protection and Development:Coordination Mechanism Research from the Perspective of Community(71373024)
文摘Three indexes including forest pest occurrence area,control area and input fund of 31 provinces from 2003 to 2014 were selected from Forestry Statistical Yearbook,to establish dynamic interaction index evaluation system with clustering robust regression model and Stata 13. 0 software. Total forest pest control efficiency in China was determined according to the computing result of entropy method. Suggestions such as improving forest pest control efficiency,increasing service efficiency and input amount of forest pest control input funds were put forward. It will provide empirical basis for target management evaluation of forest pest control work and accountability system.
文摘分析了系统温度对机抖激光陀螺捷联惯性导航系统的影响因素,介绍了降低和补偿捷联系统温度误差的4种方法。通过重复性温度实验,利用逐步回归法分析了激光陀螺零偏与温度的关系;通过多项式拟合,分别得到了加速度计的零偏、标度因子和IF转换电路的温度补偿模型,并在捷联系统中得到应用。对其中的两种方法进行了实验研究和导航测试,并对两种方法的补偿效果进行了对比。结果表明:通过温度实验得到惯性器件的温度补偿模型对其温度误差进行实时补偿是捷联系统最理想的补偿方法。补偿后系统定位测试1 h的圆概率误差(CEP)优于0.3 n mile/h,达到国内先进水平。
