Abstract In this paper, a two-stage method is proposed to solve the molten iron scheduling problem (MISP). Firstly, a 0-1 mixed-integer nonlinear programming model is established for special type of molten iron schedu...
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Abstract In this paper, a two-stage method is proposed to solve the molten iron scheduling problem (MISP). Firstly, a 0-1 mixed-integer nonlinear programming model is established for special type of molten iron scheduling problem (STMISP). A method to solve mathematical model of STMISP is presented, which include assigning machine strategy of STMISP and determining mathematical model of eliminating machine conflicts. Secondly, on the basis of results of STMISP, a heuristic algorithm based on the rule of first come first serve (FCFS) principle is established to solve normal type of molten iron scheduling problem (NTMISP). The molten iron scheduling system with the two-stage method has been successfully applied to Shanghai Baosteel Company to realize quickly optimal molten iron scheduling. Application results show that the two-stage method is both effective and feasible.
Hybrid flow shop scheduling problem (HFSP) is characterized as the scheduling of jobs in a flow shop environment where, at any stage, there may exist multiple machines. Besides the finishing time of the last job, ener...
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ISBN:
(纸本)9781424417339
Hybrid flow shop scheduling problem (HFSP) is characterized as the scheduling of jobs in a flow shop environment where, at any stage, there may exist multiple machines. Besides the finishing time of the last job, energy consumption is another important factor affecting economy benefit of hybrid flow shop. A mixed-integer nonlinear programming model is established for the HFSP with minimizing the energy consumption, according to the characteristic of HFSP in practice. It is a typical NP-hard combinatorial optimization problem. For solving it efficiently, an improved genetic algorithm is presented. The fitness based on the ranking of the energy consumption of every individual and the self-adaptive mutation operation based on the fitness are adopted. The numerical experiment is carried out on the three-two-three HFSP, and the result indicates that the model is right and the improved algorithm is efficient.
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