This paper develops an efficient variant of a Genetic Algorithm (GA) for a ship routing and scheduling problem (SRSP) with time-window in industrial shipping operation mode. This method addresses the problem of loadin...This paper develops an efficient variant of a Genetic Algorithm (GA) for a ship routing and scheduling problem (SRSP) with time-window in industrial shipping operation mode. This method addresses the problem of loading shipments for many customers using heterogeneous ships. Constraints relate to delivery time windows imposed by customers, the time horizon by which all deliveries must be made and ship capacities. The results of a computational investigation are presented and the solution quality and execution time are explored with respect to problem size. The proposed algorithm is compared, in terms of solution quality and computational time, with an exact method that uses Set Partitioning Problem (SPP). It is found that while the exact method solves small scale problem efficiently, treating large scale problems with the exact method becomes involved due to computational problem, a deficiency that the GA can encounter. Meantime, GA consistently returns better solution than other published work using Tabu Search method in term of solution quality.展开更多
多系统组合导航下可见卫星的数量显著增加,同时观测数据冗余会使移动终端的定位效率降低,而高效的选星算法能够提高动态导航的实时性.本文根据选星算法的原理,将8种选星算法划分为基于几何精度因子(geometry dilution of precision,GDOP...多系统组合导航下可见卫星的数量显著增加,同时观测数据冗余会使移动终端的定位效率降低,而高效的选星算法能够提高动态导航的实时性.本文根据选星算法的原理,将8种选星算法划分为基于几何精度因子(geometry dilution of precision,GDOP)最小的选星算法和基于空间几何分布的选星算法两类.在介绍各种选星算法原理的基础上,综合分析算法的优缺点,并通过实例验证各选星算法在GNSS四系统组合导航中的性能.展开更多
文摘This paper develops an efficient variant of a Genetic Algorithm (GA) for a ship routing and scheduling problem (SRSP) with time-window in industrial shipping operation mode. This method addresses the problem of loading shipments for many customers using heterogeneous ships. Constraints relate to delivery time windows imposed by customers, the time horizon by which all deliveries must be made and ship capacities. The results of a computational investigation are presented and the solution quality and execution time are explored with respect to problem size. The proposed algorithm is compared, in terms of solution quality and computational time, with an exact method that uses Set Partitioning Problem (SPP). It is found that while the exact method solves small scale problem efficiently, treating large scale problems with the exact method becomes involved due to computational problem, a deficiency that the GA can encounter. Meantime, GA consistently returns better solution than other published work using Tabu Search method in term of solution quality.
文摘多系统组合导航下可见卫星的数量显著增加,同时观测数据冗余会使移动终端的定位效率降低,而高效的选星算法能够提高动态导航的实时性.本文根据选星算法的原理,将8种选星算法划分为基于几何精度因子(geometry dilution of precision,GDOP)最小的选星算法和基于空间几何分布的选星算法两类.在介绍各种选星算法原理的基础上,综合分析算法的优缺点,并通过实例验证各选星算法在GNSS四系统组合导航中的性能.
