基于混合流水作业组织的港口拖轮调度优化

在对拖轮调度问题进行分析的基础之上，将拖轮调度问题归结为一类具有多阶段共用机器特征的混合流水车间调度问题. 建立了针对多停泊基地不同作业模式下、且考虑靠泊与停泊两阶段的拖轮调度优化模型，推导了基于混合流水作业组织的港口拖轮调度优化问题的理论下界值，并设计了启发式规则与模拟退火相结合的混合算法（HSA）求解该模型. 通过运用该算法求解仿真算例，并将其结果与模型理论下界值、三种基于现行调度规则及基于Johnson 规则的调度方案进行比较. 结果表明，运用HSA求解的结果与理论下界值的平均偏差值为5.39%，且该结果远小于基于现行调度规则及Johnson规则的求解值，验证了模型与算法的高效性，可以为拖轮作业模式的选择以及调度方案的制订提供决策支持.

Optimization on tugboat operation scheduling based upon the hybrid flow shop arrangement

Based on the analysis of the tugboat scheduling problem, it is formulated as a multistage hybrid flow shop scheduling problem (MHFSSP) that has the characteristics of sharing common machine sets in all stages. Combined with the scheduling theory, a tugboat scheduling model with multi-anchorage bases, different operation modes and two stages of operations (berthing/unberthing) is presented. The lower bound (LB) of the flowtime is derived from the special MHFSSP. The algorithm based on the heuristic rules and simulated annealing (HSA) is developed to solve the special MHFSSP. By the comparison of the results obtained from the algorithm with the LB and those based on three existing scheduling rules in practice and Johnson rules, the average deviation between the HSA solved results with LB is 5.39%, and the HSA solved results are far less than those from the existing scheduling rules and the Johnson rules. Thus the effectiveness and efficiency of the proposed approach were verified, which can provide supports for the decision-making on operation modes selection and operation scheduling.