Using the improved Energy-Environmental Version of the GTAP Model (GTAP-E) and the sixth version of emission database of non-CO2 greenhouse gases, we simulate the emission reduction potential of non-CO2 greenhouse gas...Using the improved Energy-Environmental Version of the GTAP Model (GTAP-E) and the sixth version of emission database of non-CO2 greenhouse gases, we simulate the emission reduction potential of non-CO2 greenhouse gases in China and its policy implications. The results show that at present, China is a country with the greatest emission of non-CO2 greenhouse gases in the world, and the emission will account for about 20% of the world's total emission in 2020. The proportion of emission of non-CO2 greenhouse gases from the agricultural sector reaches 73%. In the next 10 years, the emission of non-CO2 gases from cattle and sheep, industry and service industry will experience the highest growth rate; the growth rate of emission from service industry will be higher than that of emission from industry, and the emission from service industry will exceed that from industry after 2010. China can implement emission reduction policy of non-CO2 greenhouse gases to ease the international pressure of CO2 emission reduction. Although the high carbon tax collected can reduce considerable non-CO2 emission, there is little difference in policy efficiency between high carbon tax and low carbon tax. So, in the implementation of emission reduction carbon tax policy of non-CO2 gases, it is necessary to control the carbon tax at a low level.展开更多
Gearbox in offshore wind turbines is a component with the highest failure rates during operation. Analysis of gearbox repair policy that includes economic considerations is important for the effective operation of off...Gearbox in offshore wind turbines is a component with the highest failure rates during operation. Analysis of gearbox repair policy that includes economic considerations is important for the effective operation of offshore wind farms. From their initial perfect working states, gearboxes degrade with time, which leads to decreased working efficiency. Thus, offshore wind turbine gearboxes can be considered to be multi-state systems with the various levels of productivity for different working states. To efficiently compute the time-dependent distribution of this multi-state system and analyze its reliability, application of the nonhomogeneous continuous-time Markov process(NHCTMP) is appropriate for this type of object. To determine the relationship between operation time and maintenance cost, many factors must be taken into account, including maintenance processes and vessel requirements. Finally, an optimal repair policy can be formulated based on this relationship.展开更多
利用认知无线电非正交多址接入(cognitive radio non-orthogonal multiple access,CR-NOMA)技术可缓解频谱资源短缺问题,提升传感设备的吞吐量。传感设备的能效问题一直制约着传感设备的应用。为此,针对CR-NOMA中的传感设备,提出基于深...利用认知无线电非正交多址接入(cognitive radio non-orthogonal multiple access,CR-NOMA)技术可缓解频谱资源短缺问题,提升传感设备的吞吐量。传感设备的能效问题一直制约着传感设备的应用。为此,针对CR-NOMA中的传感设备,提出基于深度确定策略梯度的能效优化(deep deterministic policy gradientbased energy efficiency optimization,DPEE)算法。DPEE算法通过联合优化传感设备的传输功率和时隙分裂系数,提升传感设备的能效。将能效优化问题建模成马尔可夫决策过程,再利用深度确定策略梯度法求解。最后,通过仿真分析了电路功耗、时隙时长和主设备数对传感能效的影响。仿真结果表明,能效随传感设备电路功耗的增加而下降。此外,相比于基准算法,提出的DPEE算法提升了能效。展开更多
文摘Using the improved Energy-Environmental Version of the GTAP Model (GTAP-E) and the sixth version of emission database of non-CO2 greenhouse gases, we simulate the emission reduction potential of non-CO2 greenhouse gases in China and its policy implications. The results show that at present, China is a country with the greatest emission of non-CO2 greenhouse gases in the world, and the emission will account for about 20% of the world's total emission in 2020. The proportion of emission of non-CO2 greenhouse gases from the agricultural sector reaches 73%. In the next 10 years, the emission of non-CO2 gases from cattle and sheep, industry and service industry will experience the highest growth rate; the growth rate of emission from service industry will be higher than that of emission from industry, and the emission from service industry will exceed that from industry after 2010. China can implement emission reduction policy of non-CO2 greenhouse gases to ease the international pressure of CO2 emission reduction. Although the high carbon tax collected can reduce considerable non-CO2 emission, there is little difference in policy efficiency between high carbon tax and low carbon tax. So, in the implementation of emission reduction carbon tax policy of non-CO2 gases, it is necessary to control the carbon tax at a low level.
文摘Gearbox in offshore wind turbines is a component with the highest failure rates during operation. Analysis of gearbox repair policy that includes economic considerations is important for the effective operation of offshore wind farms. From their initial perfect working states, gearboxes degrade with time, which leads to decreased working efficiency. Thus, offshore wind turbine gearboxes can be considered to be multi-state systems with the various levels of productivity for different working states. To efficiently compute the time-dependent distribution of this multi-state system and analyze its reliability, application of the nonhomogeneous continuous-time Markov process(NHCTMP) is appropriate for this type of object. To determine the relationship between operation time and maintenance cost, many factors must be taken into account, including maintenance processes and vessel requirements. Finally, an optimal repair policy can be formulated based on this relationship.
