关键词: 粒子群算法, 极值理论, 广义极值分布, 优化

Abstract: Due to the randomicity of extreme events like disaster and the otherness among data，it is often faced with the uncertainty of model when calculating risks by employing extreme value theory.To avoid the fitting error caused by improperly chosen of extreme value distributing model，the generalized extreme value distribution is adopted based on the introduction of related conception of extreme value theory.And the parameters of this complicated model are optimized by particle swarm method.Flight safety assessment is exemplified in simulation，and the results show that different distributing types can be optimized analogously，at the same time，ideal results can be achieved quickly，which may provide an effective approach for exactly selecting extreme value mode.

Key words: particle swarm algorithm, extreme value theory, generalized extreme value distribution, optimization