求解柔性流水车间调度问题的高效分布估算算法

针对最小化最大完工时间的柔性流水车间调度,利用事件建模思想,线性化0-1混合整数规划模型,使得小规模调度问题通过Cplex可以准确求解,同时设计了高效分布估算算法来求解大规模调度问题.该算法采用的是一种新颖的随机规则解码方式,工件排序按选定的规则安排而机器按概率随机分配.针对分布估算算法中的概率模型不能随种群中个体各位置上工件的更新而自动调整的缺点,提出了自适应调整概率模型,该概率模型能提高分布估算算法的收敛质量和速度.同时为提高算法局部搜索能力和防止算法陷入局部最优,设计了局部搜索和重启机制.最后,采用实验设计方法校验了高效分布估算算法参数的最佳组合.算例和实例测试结果都表明本文提出的高效分布估算算法在求解质量和稳定性上均优于遗传算法、引力搜索算法和经典分布估算算法.     

具有恶化效应和学习效应的单机成组调度问题

讨论了一类具有恶化效应和学习效应的单机成组调度问题, 其中工件的加工时间为开工时间和组内工序的函数. 通过对问题性质的分析以及多项式时间算法的描述, 得出如下结论: 在单机成组调度问题中, 即便工件的加工时间同时受恶化效应和学习效应的制约, 极小化完工时间问题以及极小化总资源消耗的问题仍是多项式时间可解的.     

模糊制造系统中的不同尺寸工件单机批调度优化

将工件尺寸不同的单机批调度问题扩展到模糊制造系统中,建立了基于模糊批加工时间和模糊批间隔时间的制造跨度模型,提出了一种集成粒子群优化和差异演化的混合算法,将制造跨度最小化.为提高算法的收敛速度,设计了基于工件优先值向量的统一编码方式,并采用线性的缩放因子以确保足够的差异化信息;为解决差异演化算法早熟收敛的问题,将粒子群优化的全局搜索技术嵌入了差异演化算法;最后,在解码时利用批调度的启发式算法,将混合算法的个体加以优化分批.仿真实验结果验证了该混合算法的求解性能优于目前文献中的其他算法.     

Oppositional Red Fox Optimization Based Task Scheduling Scheme for Cloud Environment

Owing to massive technological developments in Internet of Things (IoT) and cloud environment, cloud computing (CC) offers a highly flexible heterogeneous resource pool over the network, and clients could exploit various resources on demand. Since IoT-enabled models are restricted to resources and require crisp response, minimum latency, and maximum bandwidth, which are outside the capabilities. CC was handled as a resource-rich solution to aforementioned challenge. As high delay reduces the performance of the IoT enabled cloud platform, efficient utilization of task scheduling (TS) reduces the energy usage of the cloud infrastructure and increases the income of service provider via minimizing processing time of user job. Therefore, this article concentration on the design of an oppositional red fox optimization based task scheduling scheme (ORFO-TSS) for IoT enabled cloud environment. The presented ORFO-TSS model resolves the problem of allocating resources from the IoT based cloud platform. It achieves the makespan by performing optimum TS procedures with various aspects of incoming task. The designing of ORFO-TSS method includes the idea of oppositional based learning (OBL) as to traditional RFO approach in enhancing their efficiency. A wide-ranging experimental analysis was applied on the CloudSim platform. The experimental outcome highlighted the efficacy of the ORFO-TSS technique over existing approaches.     

Coalition theory based task scheduling algorithm using DLFC-NN model

Resource management and job scheduling are essential in today's cloud computing world. Due to task scheduling and users' diverse submission of large-scale requests, co-located VM instances negatively impacted the performance of leased VM instances. This workload further led to resource rivalry across co-located VMs. In order to address the aforementioned problems, numerous strategies have been presented, however, they fail to take the asynchronous nature of the cloud environment into account. To address this issue, a novel “CTA using DLFC-NN model” is proposed. This proposed approach combines the coalition theory and DLFC-NN techniques by including IRT-OPTICS for task size clustering, digital metrology based on ionized information (DMBII) for defect detection in virtue machines (VM), and the dynamic levy flight hamster optimization algorithm for processing time optimization of the clusters. However, the implementation of task scheduling in an online environment is limited by a number of presumptions or oversimplifications made by current scheduling systems. As a result, a unique coalition theory is applied to efficiently schedule activities. In addition, the DLFC-NN model is used to reduce resource consumption, span time, and be highly accurate and energy-efficient when working on both online and offline jobs. Nevertheless, while optimizing the clusters' overall execution time, earlier approaches only decreased the make-span time for task scheduling. However, the DLFC-NN model solves the computation problem by using a fully weighted bipartite graph and the pseudo method to determine the fitness of the least makespan time. The enhanced methodology used in this study reduces the scheduling cost and minimizes job completion times according to different task counts when compared to the existing techniques.