电气工程中的设计问题常归结为多目标优化问题。对于目标函数超过三维的高维多目标优化设计,目前基于非控关系的多目标进化算法很难获得理想的优化结果。为此,人们提出了多重单目标Pareto采样(Multiple Single Objective Pareto Samplin...电气工程中的设计问题常归结为多目标优化问题。对于目标函数超过三维的高维多目标优化设计,目前基于非控关系的多目标进化算法很难获得理想的优化结果。为此,人们提出了多重单目标Pareto采样(Multiple Single Objective Pareto Sampling,MSOPS)算法。该算法结构简单,计算复杂度低。然而,研究表明,这种方法的最终优化结果往往缺乏多样性。为此,本文对MSOPS算法进行了改进研究,提出了目标矢量的拥挤操作,非均匀的目标矢量更新以及附加外部档案等改进措施以提高优化结果的多样性。通过与MSOPS-Ⅱ、HypE以及NSGA-Ⅱ算法在求解测试函数上的性能比较,证明了改进算法在Pareto解集上获得了更好的收敛性与多样性。最后,通过八木天线的优化设计验证了改进算法解决实际问题的有效性。展开更多
Chongming Island, the third largest island in China and the largest alluvial island in the world, is situated in the north of Shanghai Municipality at the mouth of the Changjiang (Yangtze) River. Along the fertile and...Chongming Island, the third largest island in China and the largest alluvial island in the world, is situated in the north of Shanghai Municipality at the mouth of the Changjiang (Yangtze) River. Along the fertile and prosperous sea coast there are a total area of over 120×103ha, with a population of 735 0 00, accruing some 500ha of new tidal land resources come from silt, sand and mud carried by the Changjiang River every year, extending about 140m per year. This dynamic process of alluvial growth has run for some 1500 years. Mudflat on Chon gming Island at the mouth of the Changjiang River is a resting ground for migrat ory birds and host more than a hundred species, including rare cranes and geese. But the local people keep reclaiming the tidal land for economic development. O bviously, it is crucial to have a well-concerted plan for future exploitation. In this study, we attempted to investigate the status changes of land use and wi ld life habitats on Chongming Island in recent 10 years, and then analyzed diffe rent human activities and their effects on wild life habitats using satellite im age data (1990, 1997 and 2000) as well as field survey. Based on the analysis, t his study explored the relationships between island growth and land use/cover ch ange (LUCC), predicted what the habitat would be like in the future and tried to find more effective use of this new growing resource. At last, this study provi ded some preliminary management plans for Chongming Island that will coordinate the development of local economies and the conservation of wild life and their h abitats.展开更多
文摘电气工程中的设计问题常归结为多目标优化问题。对于目标函数超过三维的高维多目标优化设计,目前基于非控关系的多目标进化算法很难获得理想的优化结果。为此,人们提出了多重单目标Pareto采样(Multiple Single Objective Pareto Sampling,MSOPS)算法。该算法结构简单,计算复杂度低。然而,研究表明,这种方法的最终优化结果往往缺乏多样性。为此,本文对MSOPS算法进行了改进研究,提出了目标矢量的拥挤操作,非均匀的目标矢量更新以及附加外部档案等改进措施以提高优化结果的多样性。通过与MSOPS-Ⅱ、HypE以及NSGA-Ⅱ算法在求解测试函数上的性能比较,证明了改进算法在Pareto解集上获得了更好的收敛性与多样性。最后,通过八木天线的优化设计验证了改进算法解决实际问题的有效性。
文摘Chongming Island, the third largest island in China and the largest alluvial island in the world, is situated in the north of Shanghai Municipality at the mouth of the Changjiang (Yangtze) River. Along the fertile and prosperous sea coast there are a total area of over 120×103ha, with a population of 735 0 00, accruing some 500ha of new tidal land resources come from silt, sand and mud carried by the Changjiang River every year, extending about 140m per year. This dynamic process of alluvial growth has run for some 1500 years. Mudflat on Chon gming Island at the mouth of the Changjiang River is a resting ground for migrat ory birds and host more than a hundred species, including rare cranes and geese. But the local people keep reclaiming the tidal land for economic development. O bviously, it is crucial to have a well-concerted plan for future exploitation. In this study, we attempted to investigate the status changes of land use and wi ld life habitats on Chongming Island in recent 10 years, and then analyzed diffe rent human activities and their effects on wild life habitats using satellite im age data (1990, 1997 and 2000) as well as field survey. Based on the analysis, t his study explored the relationships between island growth and land use/cover ch ange (LUCC), predicted what the habitat would be like in the future and tried to find more effective use of this new growing resource. At last, this study provi ded some preliminary management plans for Chongming Island that will coordinate the development of local economies and the conservation of wild life and their h abitats.
