As the first step of the fire/gas-detection systems of floating production storage and offloading(FPSO)units is to iden-tify leakage accidents,gas detectors play an important role in controlling the leakage risk.To im...As the first step of the fire/gas-detection systems of floating production storage and offloading(FPSO)units is to iden-tify leakage accidents,gas detectors play an important role in controlling the leakage risk.To improve the leakage scenario detection rate and reduce the cumulative risk value,this paper presents an optimization method of the gas detector placement.The probability density distribution and cumulative probability density distribution of the leakage source variables and environmental variables were calculated based on the Offshore Reliability Data and the statistical data of the relevant leakage variables.A potential leakage sce-nario set was constructed using Latin hypercube sampling.The typical FPSO leakage scenarios were analyzed through computational fluid dynamics(CFD),and the impacts of different parameters on the leakage were addressed.A series of detectors was deployed according to the simulation results.The minimization of the product of effective detection time and gas leakage volume was the risk optimization objective,and the location and number of detectors were taken as decision variables.A greedy extraction heuristic algo-rithm was used to solve the optimization problem.The results show that the optimized placement had a better monitoring effect on the leakage scenario.展开更多
After the end of the Cold War, NATO's nuclear strategy has undergone a process of evolution, so far can be divided into three phases: dissuasion strategy stage, deter war strategy stage and linkage strategy stage ...After the end of the Cold War, NATO's nuclear strategy has undergone a process of evolution, so far can be divided into three phases: dissuasion strategy stage, deter war strategy stage and linkage strategy stage and similar to nuclear strategy of other nuclear-weapon states. The NATO nuclear strategy has five specific policy components: policy on statement, policy on development, policy on deployment, policy on using nuclear arms and policies on nuclear arms control. Factors impacting NATO's nuclear strategy is multifaceted, in which strategic environment faced by NATO and NATO‘s internal debate on its major nuclear strategy are most influential, and besides the United States plays a leading role in the development of NATO's nuclear strategy.展开更多
基金support of the Fundamen-tal Research Funds for the Central Universities(No.3072021CF0101)the‘Integration Software of Offshore Float-ing Platform Engineering Design(No.2016YFC0302900)’from the Ministry of Science and Technology of China,and the Project of Development of Floating Offshore Wind Turbine Risk Assessment Software Project,funded by the International S&T Cooperation Program of China(No.2013DFE73060).
文摘As the first step of the fire/gas-detection systems of floating production storage and offloading(FPSO)units is to iden-tify leakage accidents,gas detectors play an important role in controlling the leakage risk.To improve the leakage scenario detection rate and reduce the cumulative risk value,this paper presents an optimization method of the gas detector placement.The probability density distribution and cumulative probability density distribution of the leakage source variables and environmental variables were calculated based on the Offshore Reliability Data and the statistical data of the relevant leakage variables.A potential leakage sce-nario set was constructed using Latin hypercube sampling.The typical FPSO leakage scenarios were analyzed through computational fluid dynamics(CFD),and the impacts of different parameters on the leakage were addressed.A series of detectors was deployed according to the simulation results.The minimization of the product of effective detection time and gas leakage volume was the risk optimization objective,and the location and number of detectors were taken as decision variables.A greedy extraction heuristic algo-rithm was used to solve the optimization problem.The results show that the optimized placement had a better monitoring effect on the leakage scenario.
文摘After the end of the Cold War, NATO's nuclear strategy has undergone a process of evolution, so far can be divided into three phases: dissuasion strategy stage, deter war strategy stage and linkage strategy stage and similar to nuclear strategy of other nuclear-weapon states. The NATO nuclear strategy has five specific policy components: policy on statement, policy on development, policy on deployment, policy on using nuclear arms and policies on nuclear arms control. Factors impacting NATO's nuclear strategy is multifaceted, in which strategic environment faced by NATO and NATO‘s internal debate on its major nuclear strategy are most influential, and besides the United States plays a leading role in the development of NATO's nuclear strategy.
