基于深度优先搜索算法的连铸过程调度方法的研究

炼钢连铸过程是连接铁区生产和轧制生产的桥梁,连铸是炼钢连铸过程的最后一道工序,因此连铸过程的调度成为了整个钢铁生产过程降低生产成本,保证生产有序进行的关键.本文提出了以完成时间最小化为目标的调度数学模型,通过对计划层编制的浇次计划属性与连铸机属性匹配构造出的浇次集合,采用基于启发式的深度优先搜索算法进行求解,摒弃了以往现场调度人员传统的经验调度方法,该方法已经通过了国内某大型钢铁厂实际数据的测试,不仅能够保证生产的顺利进行,同时也能够有效的辅助现场调度人员有效的降低钢铁生产的生产周期,提高钢铁生产的产能.     

Thermodynamic analysis of steam reforming of glycerol for hydrogen production at atmospheric pressure

Thermodynamic chemical equilibrium analysis of steam reforming of glycerol(SRG)for selective hydrogen production was performed based on the Gibbs free energy minimisation method.The ideal SRG reaction(C₃H₈O₃+3H₂O→3CO₂+7H₂)and a comprehensive set of side reactions during SRG are considered for the formation of a wide range of products.Specifically,this work focused on the analysis of formation of H₂,CO₂,CO and CH4 in the gas phase and determination of the carbon free region in SRG under the conditions at atmospheric pressure,600 K–1100 K and 1.013×10⁵–1.013×10⁶ Pa with the steam-to-glycerol feed ratios(SGFR)of 1:5–10.The reaction conditions which favoured SRG for H₂ production with minimum coke formation were identifies as:atmospheric pressure,temperatures of 900 K–1050 K and SGFR of 10:1.The influence of using the inert carrier gas(i.e.,N₂)in SRG was studied as well at atmospheric pressure.Although the presence of N₂ in the stream decreased the partial pressure of reactants,it was beneficial to improve the equilibrium yield of H₂.Under both conditions of SRG(with/without inert gas),the CH4 production is minimised,and carbon formation was thermodynamically unfavoured at steam rich conditions of SGFR>5:1.     

基于最小完工期的离散型作业车间调度问题的遗传算法设计

针对离散型生产作业中的车间调度问题,以完工期最小为目标,设计了遗传算法,并利用PB语言编程实现该算法.最后,将该算法应用于某一钢铁公司金工车间的车间调度,并与原调度的结果做了比较,证明了本算法在实际应用中的有效性.     

Scheduling trees with large communication delays on two identical processors

We consider the problem of scheduling trees on two identical processors in order to minimize the makespan. We assume that tasks have unit execution times, and arcs are associated with large identical integer communication delays. We prove that the problem is NP-hard in the strong sense even when restricted to the class of binary trees, and we provide a polynomial-time algorithm for complete binary trees.This work has been partially supported by the French-Greek bilateral exchange program PLATON and the GDR-PRS Ordonnancement pour le parallélisme program of the French government.     

求解Job-Shop调度问题的禁忌搜索算法的研究

本文针对最小完工时间的Job-Shop调度问题提出了一种禁忌搜索算法，该算法使用插入算法构造尽可能好的初始解，然后用禁忌搜索算法改进当前解，在算法中对未被选中的候选解信息进行记忆，合理平衡了集中搜索与分散搜索。最后用基准实例进行仿真，实验结果表明该算法是可行的和有效的。     

一种改进的启发式网格任务调度算法

网格任务调度算法是影响网格成功与否的关键技术之一。网格计算中,一个好的任务调度算法不但要考虑所有任务的makespan,使其值尽量小,同样要考虑到整个系统机器间的负载平衡问题。文章对异构计算环境下的元任务调度算法进行了分析,针对Min-min算法可能引发的负载不平衡问题,结合网格计算环境的特点,提出了一种适用于网格计算环境中的任务调度算法。     

混合流水车间的遗传算法调度策略(英文)

应用遗传算法对混合流水车间的总作业时间最小的调度问题进行了研究。混合流水车间是一类特殊的流水车间环境,但其每一级可以有多个机床。所提出的算法基于表调度原理,首先给出在第一级工件的排列顺序,并在其后的各级采用先入先出（FIFO）方式。试验表明,所提出的遗传算法调度策略优先于原有的启发式及随机搜索方法。     

Visibility enhancement of fog-degraded image using adaptive total variation minimisation

Images degraded due to bad weather conditions affect the quality of vision-based security systems, as the distortions obscure contrasts in the frames of the images. In this paper, we present a novel approach that uses adaptive total variation minimisation to retain the object and reduce the noise from a single image, thereby enhancing fog-degraded images. Representative experimental results show that our proposed algorithm is effective for contrast and saturation enhancement of fog-degraded images.     

改进的人工免疫算法在管子生产调度中的应用

造船企业管子加工生产的生产模式可以归结为一种混合流水生产线.本文针对这类管子混合流水生产线,采用一种改进的免疫算法对生产过程进行调度,通过引入免疫记忆因子,有效实现了优良抗体基因的保留和利用,从而提高了算法收敛性和鲁棒性.通过利用管子生产厂实际生产模型进行仿真后发现,利用该算法得到的序列进行调度确实能够有效缩短管子最大流程时间和提高实际生产效率.     

一类解决无等待流水车间调度问题的蚁群算法

针对以最大完成时间为目标的无等待流水车间调度问题,提出了一种蚁群算法.首先,基于复杂度为O(n)的最大完成时间算法简化了适应值的计算;其次,基于当前最优解和轨迹密度的新解构造方法提高了求解质量;第三,基于快速插入邻域算法的多重插入移动提高了搜索效率;最后,基于典型算例的仿真试验,表明了所得调度算法的可行性和优越性.