An improved Guo Tao algorithm （IGT algorithm） is proposed for solving complicated dynamic function optimization problems, and a function optimization benchmark problem with constrained condition and two dynamic para...An improved Guo Tao algorithm （IGT algorithm） is proposed for solving complicated dynamic function optimization problems, and a function optimization benchmark problem with constrained condition and two dynamic parameters has been designed. The results achieved by IGT algorithm have been compared with the results from the Guo Tao algorithm （GT algorithm）. It is shown that the new algorithm （IGT algorithm） provides better results. This preliminarily demonstrates the efficiency of the new algorithm in complicated dynamic environments.展开更多
This paper presents a parallel two-level evolutionary algorithm based on domain decomposition for solving function optimization problem containing multiple solutions. By combining the characteristics of the global sea...This paper presents a parallel two-level evolutionary algorithm based on domain decomposition for solving function optimization problem containing multiple solutions. By combining the characteristics of the global search and local search in each sub-domain, the former enables individual to draw closer to each optima and keeps the diversity of individuals, while the latter selects local optimal solutions known as latent solutions in sub-domain. In the end, by selecting the global optimal solutions from latent solutions in each sub-domain, we can discover all the optimal solutions easily and quickly.展开更多
基于模型的安全性分析方法能够提高复杂安全关键系统的建模与分析能力。目前故障树被广泛应用于系统安全及可靠性分析中。故障树分析(Fault Tree Analysis,FTA)是一种自上而下的演绎式失效方法,根据故障树分析系统中不希望出现的状态,...基于模型的安全性分析方法能够提高复杂安全关键系统的建模与分析能力。目前故障树被广泛应用于系统安全及可靠性分析中。故障树分析(Fault Tree Analysis,FTA)是一种自上而下的演绎式失效方法,根据故障树分析系统中不希望出现的状态,系统工程中可以尽早确定当前系统模型可能出现的问题并及时避免。面向一类安全关键性系统领域中的系统安全性建模语言AltaRica,基于其语义模型卫士转换系统(Guarded Transition Systems,GTS),设计了从平展化的GTS模型自动构造系统故障树的方法,节省了人工构造故障树的时间,从而加快了系统分析的进度。根据AltaRica3.0语言的语义规则,提取平展化GTS模型的数据构建实例对象;设计了GTS模型划分算法,得到一组独立GTS模型与一个独立断言,通过邻接矩阵构建独立GTS的可达图并获取关键事件序列。最后将处理结束的独立GTS与独立断言相结合,通过断言传播算法得到整个系统的状态及关键事件序列,生成系统故障树。最后通过实例来检验算法的有效性,结果表明,该算法能有效完成从平展化GTS模型自动生成故障树。展开更多
为了提高柴油机的燃油经济性,文章利用遗传算法对带有废气再循环(exhaust gas recirculation,EGR)系统的涡轮增压柴油机空气系统进行参数优化。以发动机有效燃油消耗率为优化目标,NO_(x)与Soot排放为约束,EGR阀开度与可变截面涡轮增压...为了提高柴油机的燃油经济性,文章利用遗传算法对带有废气再循环(exhaust gas recirculation,EGR)系统的涡轮增压柴油机空气系统进行参数优化。以发动机有效燃油消耗率为优化目标,NO_(x)与Soot排放为约束,EGR阀开度与可变截面涡轮增压器的叶片开度为优化参数,利用开发的GT-Power与Matlab/Simulink联合仿真程序进行遗传算法寻优。全负荷工况下的寻优结果表明,寻优后燃油消耗率相较于原机下降了1.21~2.42 g/(kW·h),通过遗传算法优化的空气系统参数能明显改善柴油机的燃油经济性。最后根据发动机各个工况的优化结果,绘制了EGR阀开度map与涡轮增压系统(variable geometry turbocharger,VGT)叶片开度map。展开更多
基金Supported by the National Natural Science Foundation of China(60473081,60133010)
文摘An improved Guo Tao algorithm （IGT algorithm） is proposed for solving complicated dynamic function optimization problems, and a function optimization benchmark problem with constrained condition and two dynamic parameters has been designed. The results achieved by IGT algorithm have been compared with the results from the Guo Tao algorithm （GT algorithm）. It is shown that the new algorithm （IGT algorithm） provides better results. This preliminarily demonstrates the efficiency of the new algorithm in complicated dynamic environments.
基金Supported by the National Natural Science Foundation of China(60133010,60073043,70071042)
文摘This paper presents a parallel two-level evolutionary algorithm based on domain decomposition for solving function optimization problem containing multiple solutions. By combining the characteristics of the global search and local search in each sub-domain, the former enables individual to draw closer to each optima and keeps the diversity of individuals, while the latter selects local optimal solutions known as latent solutions in sub-domain. In the end, by selecting the global optimal solutions from latent solutions in each sub-domain, we can discover all the optimal solutions easily and quickly.
文摘基于模型的安全性分析方法能够提高复杂安全关键系统的建模与分析能力。目前故障树被广泛应用于系统安全及可靠性分析中。故障树分析(Fault Tree Analysis,FTA)是一种自上而下的演绎式失效方法,根据故障树分析系统中不希望出现的状态,系统工程中可以尽早确定当前系统模型可能出现的问题并及时避免。面向一类安全关键性系统领域中的系统安全性建模语言AltaRica,基于其语义模型卫士转换系统(Guarded Transition Systems,GTS),设计了从平展化的GTS模型自动构造系统故障树的方法,节省了人工构造故障树的时间,从而加快了系统分析的进度。根据AltaRica3.0语言的语义规则,提取平展化GTS模型的数据构建实例对象;设计了GTS模型划分算法,得到一组独立GTS模型与一个独立断言,通过邻接矩阵构建独立GTS的可达图并获取关键事件序列。最后将处理结束的独立GTS与独立断言相结合,通过断言传播算法得到整个系统的状态及关键事件序列,生成系统故障树。最后通过实例来检验算法的有效性,结果表明,该算法能有效完成从平展化GTS模型自动生成故障树。
