基于FLP的再制造物流网络不确定性问题

通过分析再制造逆向物流网络模型中不确定性因素存在的原因,提出选取单位观测时间T的方法反映废旧品产生时间和地点的不确定,用模糊变量反映废旧品数量和质量的不确定,并提出基于轮盘赌的采样模糊模拟方法确定模糊数的隶属函数,使得模型能够充分利用现场信息.以投资成本和运输成本最低为目标函数建立了模糊线性规划模型,使所建模型能考虑更多的不确定因素,改变了以往模型简单假设不确定带来的问题.结合实际算例,采用混合智能算法求解,得到了优化结果,验证了模型的有效性.通过对模型中各参数进行比较分析,体现了不同机会约束中的置信水平的高低对选址策略的影响变化规律.     

Scheduling Rules Based on Gene Expression Programming for Resource-Constrained Project Scheduling Problem

In order to minimize the project duration of resourceconstrained project scheduling problem( RCPSP), a gene expression programming-based scheduling rule( GEP-SR) method is proposed to automatically discover and select the effective scheduling rules( SRs) which are constructed using the project status and attributes of the activities. SRs are represented by the chromosomes of GEP, and an improved parallel schedule generation scheme( IPSGS) is used to transform the SRs into explicit schedules. The framework of GEP-SR for RCPSP is designed,and the effectiveness of the GEP-SR approach is demonstrated by comparing with other methods on the same instances.