1,352 research outputs found
A similarity-based cooperative co-evolutionary algorithm for dynamic interval multi-objective optimization problems
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Dynamic interval multi-objective optimization problems (DI-MOPs) are very common in real-world applications. However, there are few evolutionary algorithms that are suitable for tackling DI-MOPs up to date. A framework of dynamic interval multi-objective cooperative co-evolutionary optimization based on the interval similarity is presented in this paper to handle DI-MOPs. In the framework, a strategy for decomposing decision variables is first proposed, through which all the decision variables are divided into two groups according to the interval similarity between each decision variable and interval parameters. Following that, two sub-populations are utilized to cooperatively optimize decision variables in the two groups. Furthermore, two response strategies, rgb0.00,0.00,0.00i.e., a strategy based on the change intensity and a random mutation strategy, are employed to rapidly track the changing Pareto front of the optimization problem. The proposed algorithm is applied to eight benchmark optimization instances rgb0.00,0.00,0.00as well as a multi-period portfolio selection problem and compared with five state-of-the-art evolutionary algorithms. The experimental results reveal that the proposed algorithm is very competitive on most optimization instances
Stability of -orbital Bose-Einstein condensates in optical checkerboard and square lattices
We investigate -orbital Bose-Einstein condensates in both the square and
checkerboard lattice by numerically solving the Gross-Pitaevskii equation. The
periodic potential for the latter lattice is taken exactly from the recent
experiment [Nature Phys. 7, 147 (2011)]. It is confirmed that the staggered
orbital-current state is the lowest-energy state in the band. Our numerical
calculation further reveals that for both lattices the staggered -orbital
state suffers Landau instability but the situation is remarkably different for
dynamical instability. A dynamically stable parameter region is found for the
checkerboard lattice, but not for the square.Comment: 7 pages, 7 figure
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