Production scheduling has a major impact on the productivity of the manufacturing process. Recently, scheduling problems with deteriorating jobs have attracted increasing attentions from researchers. In many practical...Production scheduling has a major impact on the productivity of the manufacturing process. Recently, scheduling problems with deteriorating jobs have attracted increasing attentions from researchers. In many practical situations,it is found that some jobs fail to be processed prior to the pre-specified thresholds,and they often consume extra deteriorating time for successful accomplishment. Their processing times can be characterized by a step-wise function. Such kinds of jobs are called step-deteriorating jobs. In this paper,parallel machine scheduling problem with stepdeteriorating jobs( PMSD) is considered. Due to its intractability,four different mixed integer programming( MIP) models are formulated for solving the problem under consideration. The study aims to investigate the performance of these models and find promising optimization formulation to solve the largest possible problem instances. The proposed four models are solved by commercial software CPLEX. Moreover,the near-optimal solutions can be obtained by black-box local-search solver LocalS olver with the fourth one. The computational results show that the efficiencies of different MIP models depend on the distribution intervals of deteriorating thresholds, and the performance of LocalS olver is clearly better than that of CPLEX in terms of the quality of the solutions and the computational time.展开更多
为了最大化延长无线传感网络寿命,设计最优的基站移动模型,提出了基于混合整数规划MIP(Mixed Integer Programming)的高斯移动方案MIP-BSM(MIP-based Gaussian Base Station Mobility)。该方案首先选择较大的标准方差,并依据此方差和零...为了最大化延长无线传感网络寿命,设计最优的基站移动模型,提出了基于混合整数规划MIP(Mixed Integer Programming)的高斯移动方案MIP-BSM(MIP-based Gaussian Base Station Mobility)。该方案首先选择较大的标准方差,并依据此方差和零均值产生基站的候选位置,然后使用这些候选位置执行MIP模型,获取基站移动的最优位置。仿真结果表明,与随机移动模型相比,MIP-BSM能够获取更长的网络寿命。展开更多
信标的受控性是检测柔性制造系统(flexible manufacturing system,FMS)Petri网模型是否存在死锁的关键因素.对于普通Petri网,在任何可达标识下所有信标不被清空是检测网系统非死锁的充分条件.然而,该条件对于建模能力更强的一般Petri网...信标的受控性是检测柔性制造系统(flexible manufacturing system,FMS)Petri网模型是否存在死锁的关键因素.对于普通Petri网,在任何可达标识下所有信标不被清空是检测网系统非死锁的充分条件.然而,该条件对于建模能力更强的一般Petri网并不适用,max可控性条件由此产生.研究证明,该条件对于一般Petri网的死锁检测过于严格了.虽然其后有很多研究者通过改进max可控性条件以求给出条件更宽松的一般Petri网非死锁的充分条件,但大部分的研究成果都仅仅局限于一种顺序资源共享分配系统Petri网模型S4PR(systems of sequential systems with shared resources)网.因此,本文在max可控性条件的基础上提出了新的名为max#可控的信标可控性条件,并在此条件的基础上实现了基于混合整数规划(mixed integer programming,MIP)的死锁检测方法.与现有研究成果相比,max#可控性条件更宽松,可适用于更多类型的一般网,为解决大规模柔性制造系统中死锁监督控制器的结构复杂性问题提供了有力的理论支撑.展开更多
本文提出了表征一个Petri网子类,即S4R网(system of sequential systems with shared resources)中死锁问题的必需信标的概念和一种将混合整数规划算法与必需信标控制相结合的死锁预防策略.在该策略的迭代过程中,混合整数规划算法发现...本文提出了表征一个Petri网子类,即S4R网(system of sequential systems with shared resources)中死锁问题的必需信标的概念和一种将混合整数规划算法与必需信标控制相结合的死锁预防策略.在该策略的迭代过程中,混合整数规划算法发现被控的Petri网中是否存在最大的死标识信标,若存在,则通过库所分类和迭代式的信标提取,得到必需信标,添加相应的控制库所,满足必需信标的最大可控性,从而实现被控的Petri网活性的目的.理论分析和算例验证表明了该策略的正确性和有效性.展开更多
基金National Natural Science Foundation of China(No.51405403)the Fundamental Research Funds for the Central Universities,China(No.2682014BR019)the Scientific Research Program of Education Bureau of Sichuan Province,China(No.12ZB322)
文摘Production scheduling has a major impact on the productivity of the manufacturing process. Recently, scheduling problems with deteriorating jobs have attracted increasing attentions from researchers. In many practical situations,it is found that some jobs fail to be processed prior to the pre-specified thresholds,and they often consume extra deteriorating time for successful accomplishment. Their processing times can be characterized by a step-wise function. Such kinds of jobs are called step-deteriorating jobs. In this paper,parallel machine scheduling problem with stepdeteriorating jobs( PMSD) is considered. Due to its intractability,four different mixed integer programming( MIP) models are formulated for solving the problem under consideration. The study aims to investigate the performance of these models and find promising optimization formulation to solve the largest possible problem instances. The proposed four models are solved by commercial software CPLEX. Moreover,the near-optimal solutions can be obtained by black-box local-search solver LocalS olver with the fourth one. The computational results show that the efficiencies of different MIP models depend on the distribution intervals of deteriorating thresholds, and the performance of LocalS olver is clearly better than that of CPLEX in terms of the quality of the solutions and the computational time.
文摘为了最大化延长无线传感网络寿命,设计最优的基站移动模型,提出了基于混合整数规划MIP(Mixed Integer Programming)的高斯移动方案MIP-BSM(MIP-based Gaussian Base Station Mobility)。该方案首先选择较大的标准方差,并依据此方差和零均值产生基站的候选位置,然后使用这些候选位置执行MIP模型,获取基站移动的最优位置。仿真结果表明,与随机移动模型相比,MIP-BSM能够获取更长的网络寿命。
文摘信标的受控性是检测柔性制造系统(flexible manufacturing system,FMS)Petri网模型是否存在死锁的关键因素.对于普通Petri网,在任何可达标识下所有信标不被清空是检测网系统非死锁的充分条件.然而,该条件对于建模能力更强的一般Petri网并不适用,max可控性条件由此产生.研究证明,该条件对于一般Petri网的死锁检测过于严格了.虽然其后有很多研究者通过改进max可控性条件以求给出条件更宽松的一般Petri网非死锁的充分条件,但大部分的研究成果都仅仅局限于一种顺序资源共享分配系统Petri网模型S4PR(systems of sequential systems with shared resources)网.因此,本文在max可控性条件的基础上提出了新的名为max#可控的信标可控性条件,并在此条件的基础上实现了基于混合整数规划(mixed integer programming,MIP)的死锁检测方法.与现有研究成果相比,max#可控性条件更宽松,可适用于更多类型的一般网,为解决大规模柔性制造系统中死锁监督控制器的结构复杂性问题提供了有力的理论支撑.
基金国家自然科学基金资助项目(6077300161074035+4 种基金61064003)教育部高等学校博士点基金资助项目(20090203110009)国家高科技发展规划"863"计划资助项目(2008AA04Z109)西安电子科技大学基本科研业务费资助项目Alexander von Humboldt Foundation研究基金资助项目
文摘本文提出了表征一个Petri网子类,即S4R网(system of sequential systems with shared resources)中死锁问题的必需信标的概念和一种将混合整数规划算法与必需信标控制相结合的死锁预防策略.在该策略的迭代过程中,混合整数规划算法发现被控的Petri网中是否存在最大的死标识信标,若存在,则通过库所分类和迭代式的信标提取,得到必需信标,添加相应的控制库所,满足必需信标的最大可控性,从而实现被控的Petri网活性的目的.理论分析和算例验证表明了该策略的正确性和有效性.
