In this paper a hybrid process of modeling and optimization, which integrates a support vector machine （SVM） and genetic algorithm （GA）, was introduced to reduce the high time cost in structural optimization of sh...In this paper a hybrid process of modeling and optimization, which integrates a support vector machine （SVM） and genetic algorithm （GA）, was introduced to reduce the high time cost in structural optimization of ships. SVM, which is rooted in statistical learning theory and an approximate implementation of the method of structural risk minimization, can provide a good generalization performance in metamodeling the input-output relationship of real problems and consequently cuts down on high time cost in the analysis of real problems, such as FEM analysis. The GA, as a powerful optimization technique, possesses remarkable advantages for the problems that can hardly be optimized with common gradient-based optimization methods, which makes it suitable for optimizing models built by SVM. Based on the SVM-GA strategy, optimization of structural scantlings in the midship of a very large crude carrier （VLCC） ship was carried out according to the direct strength assessment method in common structural rules （CSR）, which eventually demonstrates the high efficiency of SVM-GA in optimizing the ship structural scantlings under heavy computational complexity. The time cost of this optimization with SVM-GA has been sharply reduced, many more loops have been processed within a small amount of time and the design has been improved remarkably.展开更多
文中利用水动力分析软件AQWA研究了单点系泊FPSO(floating production,storage and offloading system)与油轮串靠外输时的水动力干扰及不同内转塔位置下串靠外输系统的运动响应,分析了不同转塔位置对FPSO风标效应及外输安全性的影响....文中利用水动力分析软件AQWA研究了单点系泊FPSO(floating production,storage and offloading system)与油轮串靠外输时的水动力干扰及不同内转塔位置下串靠外输系统的运动响应,分析了不同转塔位置对FPSO风标效应及外输安全性的影响.计算结果表明串靠外输时两船的装载情况对水动力干扰影响较大,低频波浪入射时串靠驳船的存在对FPSO二阶漂移力的影响较大,不同的转塔位置对FPSO-油轮系统风标效应存在显著影响.文中计算的4种工况中,FPSO内转塔位置距船艏约25%船长处最合理,风标效应较强且外输安全性较高.文中的计算及分析结果对内转塔式FPSO及外输系统的设计具有一定指导意义.展开更多
基金Supported by the Project of Ministry of Education and Finance (No.200512)the Project of the State Key Laboratory of Ocean Engineering (GKZD010053-10)
文摘In this paper a hybrid process of modeling and optimization, which integrates a support vector machine （SVM） and genetic algorithm （GA）, was introduced to reduce the high time cost in structural optimization of ships. SVM, which is rooted in statistical learning theory and an approximate implementation of the method of structural risk minimization, can provide a good generalization performance in metamodeling the input-output relationship of real problems and consequently cuts down on high time cost in the analysis of real problems, such as FEM analysis. The GA, as a powerful optimization technique, possesses remarkable advantages for the problems that can hardly be optimized with common gradient-based optimization methods, which makes it suitable for optimizing models built by SVM. Based on the SVM-GA strategy, optimization of structural scantlings in the midship of a very large crude carrier （VLCC） ship was carried out according to the direct strength assessment method in common structural rules （CSR）, which eventually demonstrates the high efficiency of SVM-GA in optimizing the ship structural scantlings under heavy computational complexity. The time cost of this optimization with SVM-GA has been sharply reduced, many more loops have been processed within a small amount of time and the design has been improved remarkably.
文摘文中利用水动力分析软件AQWA研究了单点系泊FPSO(floating production,storage and offloading system)与油轮串靠外输时的水动力干扰及不同内转塔位置下串靠外输系统的运动响应,分析了不同转塔位置对FPSO风标效应及外输安全性的影响.计算结果表明串靠外输时两船的装载情况对水动力干扰影响较大,低频波浪入射时串靠驳船的存在对FPSO二阶漂移力的影响较大,不同的转塔位置对FPSO-油轮系统风标效应存在显著影响.文中计算的4种工况中,FPSO内转塔位置距船艏约25%船长处最合理,风标效应较强且外输安全性较高.文中的计算及分析结果对内转塔式FPSO及外输系统的设计具有一定指导意义.
