In view of complex optimization problems with high nonlinearity and multiple extremums,harmony search algorithm has problems of slow convergence speed,being easy to be stalled and difficult to combine global search wi...In view of complex optimization problems with high nonlinearity and multiple extremums,harmony search algorithm has problems of slow convergence speed,being easy to be stalled and difficult to combine global search with local search.Therefore,a global competitive harmonic search algorithm based on stochastic attraction is proposed.Firstly,by introducing the stochastic attraction model to adjust the harmonic vector,the harmonic search algorithm was greatly improved and prone to fall into the local optimum.Secondly,the competitive search strategy was made to generate two harmony vectors for each iteration and make competitive selection.The adaptive global adjustment and local search strategy were designed to effectively balance the global and local search capabilities of the algorithm.The typical test function was used to test the algorithm.The experimental results show that the algorithm has high precision and the ability to find the global optimum compared with the existing algorithms.The overall accuracy is increased by more than 50%.展开更多
China is expected to join the World Trade Organization (WTO), which means that China will be doubtlessly involved in global competi-tion. Auto trade maintains an important portion of the overall world trade. In this c...China is expected to join the World Trade Organization (WTO), which means that China will be doubtlessly involved in global competi-tion. Auto trade maintains an important portion of the overall world trade. In this case, China’s auto industry shall get ready for worldwide com-petition and proper competition strategies展开更多
The 8th edition of the Global Trajectory Optimization Competition(GTOC8)presented a novel concept of a space-based very-long-baseline interferometry(VLBI)telescope in cislunar space for observing selected radio source...The 8th edition of the Global Trajectory Optimization Competition(GTOC8)presented a novel concept of a space-based very-long-baseline interferometry(VLBI)telescope in cislunar space for observing selected radio sources in cosmos.It requires designing a three-spacecraft triangular formation with changeable sizes and orientations such that observation can be scheduled as efficiently as possible.We first review the problem,and then describe the methods employed by representative teams participating in the competition.Subsequently,we present the design techniques employed by the team from the Chinese Academy of Sciences,which are primarily based on orbital-geometry analysis.Two efficient trajectory patterns are summarized:million-kilometer triangular formations with symmetric circular orbits,and consecutive-lunar-flyby trajectories with Moon-to-Moon transfer orbits.These two trajectory patterns enable establishing and reconfiguring the triangular formation with sufficiently different sizes so that a number of radio sources can be observed,thus maximizing the performance index.Finally,we present a solution with the best currently known score of J=158 million km.展开更多
文摘In view of complex optimization problems with high nonlinearity and multiple extremums,harmony search algorithm has problems of slow convergence speed,being easy to be stalled and difficult to combine global search with local search.Therefore,a global competitive harmonic search algorithm based on stochastic attraction is proposed.Firstly,by introducing the stochastic attraction model to adjust the harmonic vector,the harmonic search algorithm was greatly improved and prone to fall into the local optimum.Secondly,the competitive search strategy was made to generate two harmony vectors for each iteration and make competitive selection.The adaptive global adjustment and local search strategy were designed to effectively balance the global and local search capabilities of the algorithm.The typical test function was used to test the algorithm.The experimental results show that the algorithm has high precision and the ability to find the global optimum compared with the existing algorithms.The overall accuracy is increased by more than 50%.
文摘China is expected to join the World Trade Organization (WTO), which means that China will be doubtlessly involved in global competi-tion. Auto trade maintains an important portion of the overall world trade. In this case, China’s auto industry shall get ready for worldwide com-petition and proper competition strategies
基金supported by the National Natural Science Foundation of China(No.11372311)the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-KT-2019-1).
文摘The 8th edition of the Global Trajectory Optimization Competition(GTOC8)presented a novel concept of a space-based very-long-baseline interferometry(VLBI)telescope in cislunar space for observing selected radio sources in cosmos.It requires designing a three-spacecraft triangular formation with changeable sizes and orientations such that observation can be scheduled as efficiently as possible.We first review the problem,and then describe the methods employed by representative teams participating in the competition.Subsequently,we present the design techniques employed by the team from the Chinese Academy of Sciences,which are primarily based on orbital-geometry analysis.Two efficient trajectory patterns are summarized:million-kilometer triangular formations with symmetric circular orbits,and consecutive-lunar-flyby trajectories with Moon-to-Moon transfer orbits.These two trajectory patterns enable establishing and reconfiguring the triangular formation with sufficiently different sizes so that a number of radio sources can be observed,thus maximizing the performance index.Finally,we present a solution with the best currently known score of J=158 million km.
