共查询到20条相似文献,搜索用时 140 毫秒
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改进伪并行遗传算法求解作业车间调度问题 总被引:1,自引:0,他引:1
针对遗传算法在求解极复杂优化问题中出现的过早收敛、执行效率差的缺点,提出了一种改进的伪并行遗传算法.该算法将并行进化与串行搜索相结合,提高了算法的收敛速度.同时该算法通过种群因子控制伪并行算法中的各子种群的规模,不仅保证了搜索过程中勘探和开采的平衡,克服过早收敛,而且减少了计算的复杂性,特别是在处理复杂优化问题上具有较高的性能.实验结果证明了该算法的有效性. 相似文献
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基于二阶锥权互补函数,将二阶锥权互补问题转化为一个方程组,运用非精确非内点连续化算法求解该方程组.该算法能以任意点作为初始点,且每次迭代时至多求解一个方程组.为节省算法求解方程组时的计算时间和内存,将非精确牛顿法引入到算法中.在适当假设下,证明了该算法是全局与局部二阶收敛的.最后数值实验表明了算法的良好性能. 相似文献
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王松波 《数学的实践与认识》2022,(9):132-146
大多数现有的进化算法在处理多目标优化问题(multi-objective optimization problem,MOP)时会遇到Pareto最优解稀疏的困难,特别是当决策变量的数目很大时,如旨在从大量候选特征中找出小部分特征的特征选择.为此,提出了一种求解大规模稀疏MOP的进化算法.算法考虑Pareto最优解的稀疏性,提出了一种新的种群初始化策略和遗传算子,以保证解的稀疏性.此外,还设计了一个测试套件来评估该算法在大规模稀疏MOP中的性能,实验结果和应用实例证明了该算法在处理大规模稀疏MOP问题上的优越性. 相似文献
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基于谱梯度法和著名LS共轭梯度法的结构,该文建立了求解凸约束非线性伪单调方程组问题的谱LS型无导数投影算法.通过构建适当的谱参数,该算法在每一次迭代中都能保证搜索方向的充分下降性,并且独立于线搜索条件.在适当的假设条件和经典无导数线搜索条件下,算法具有全局收敛性.通过数值实验发现,该算法继承了LS共轭梯度法优秀的计算性能,并提高了稳定性. 相似文献
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Steiner最优树问题是指对于给定区域内的点集,通过引入Steiner点集将区域中的点连接并保证连通的网络达到最小.该问题已成为经典的优化组合问题之一.提出一种基于模拟植物生长算法生成Steiner最优树的连通算法来实现网络连通.通过对实例的实验及结果分析,结果表明本算法不仅可获得最优解,精度和性能也有提高,明显优于其它方法. 相似文献
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带组约束可靠性网络最优化问题的精确算法 总被引:1,自引:0,他引:1
本文提出了一种求解带组约束串-并网络系统最优冗余问题的精确算法.该算法利用拉格朗日松驰和Dantzig-Wolfe分解法得到问题的上界,并结合动态规划求解子问题.算法采用一种有效的切割和剖分方法,以逐步缩小对偶间隙和保证收敛性.数值结果表明该算法对于求解带组约束可靠性最优化问题是很有效的. 相似文献
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本文把拓展熵规划转化为锥最优化问题,再对该锥最优化问题构造一个锥自对偶嵌入模型,证明了锥自对偶嵌入模型的障碍函数满足自协调性,这保证了用某些内点法求解时算法是多项式时间的.这种方法的另一个优点是不需要寻找初始可行解. 相似文献
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We investigate a scheduling problem with job delivery coordination in which the machine has a maintenance time interval. The goal is to minimize the makespan. In the problem, each job needs to be processed on the machine non-preemptively for a certain time, and then transported to a distribution center, by one vehicle with a limited physical capacity. We present a 2-approximation algorithm for the problem, and show that the performance ratio is tight. 相似文献
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Parviz Fattahi Seyed Mohammad Hassan Hosseini Fariborz Jolai Reza Tavakkoli-Moghaddam 《Applied Mathematical Modelling》2014
A hybrid flow shop scheduling problem (HFSP) with assembly operations is studied in this paper. In the considered problem, a number of products of the same kind are produced. Each product is assembled using a set of several parts. At first, the parts are produced in a hybrid flow shop and then they are assembled in an assembly stage to produce products. The considered objective is to minimize the completion time of all products (makespan). This problem has been proved strongly NP-hard, so in order to solve it, a hierarchical branch and bound algorithm is presented. Also, some lower and upper bounds are developed to increase the efficiency of the proposed algorithm. The numerical experiments are used to evaluate the performance of the proposed algorithm. 相似文献
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The paper deals with the problem of scheduling jobs on a single machine, in which each job has a release date, a delivery time and a controllable processing time, having its own associated linearly varying cost. An approximation algorithm for minimizing the overall schedule cost is provided which has the performance guarantee of
, where is the worst-case performance bound of a procedure used in the proposed algorithm for solving the pure sequencing problem. The best approximation procedure known has
. 相似文献
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超尺寸物品装箱问题及其算法 总被引:3,自引:0,他引:3
本文探讨一类新装箱问题-超尺寸物品装箱问题。针对实际解决该问题的两涉法,我们提出了一个评价效率更高的目标函数,证明了在此目标函数下两步法的渐近最坏比不小于2,并给出了渐近量坏比与拆分次数的关系。最后本文提出了一种不同于两步法的新在线算法MA,证明了在新目标函数下其渐近最坏比不超过7/4。 相似文献
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This paper considers an integrated service network design problem for a given set of freight demands that is concerned with integration of locating cross-docking (CD) centers and allocating vehicles for the associated direct (transportation) services from origin node to a CD center or from a CD center to the destination node. For the vehicle allocation, direct services (sub-routes) should be determined for the given freight demands, and then the vehicle allocation has to be made in consideration of routing for the associated direct service fulfillment subject to vehicle capacity and service time restriction. The problem is modeled as a path-based formulation for which a tabu-search-based solution algorithm is proposed. To guarantee the performance of the proposed solution algorithm, strong valid inequalities are derived based on the polyhedral characteristics of the problem domain and an efficient separation heuristic is derived for identifying any violated valid inequalities. Computational experiments are performed to test the performance of the proposed solution algorithm and also that of a valid-inequality separation algorithm, which finds that the solution algorithm works quite well and the separation algorithm provides strengthened lower bounds. Its immediate application may be made to strategic (integrated) service network designs and to tactical service network planning for the CD network. 相似文献
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This paper considers two scheduling problems for a two-machine flowshop where a single machine is followed by a batching machine. The first problem is that there is a transporter to carry the jobs between machines. The second problem is that there are deteriorating jobs to be processed on the single machine. For the first problem with minimizing the makespan, we formulate it as a mixed integer programming model and then prove that it is strongly NP-hard. A heuristic algorithm is proposed for solving this problem and its worst case performance is analyzed. The computational experiments are carried out and the numerical results show that the heuristic algorithm is effective. For the second problem, we derive the optimal algorithms with polynomial time for minimizing the makespan, the total completion time and the maximum lateness, respectively. 相似文献
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在K-SVCR算法结构的基础上构造了新的模型.模型的特点是它的一阶最优化条件可以转化为一个线性互补问题,通过Lagrangian隐含数,可以将其进一步转化成一个强凸的无约束优化问题.利用共轭梯度技术对其进行求解,在有限步内得到分类超平面.最后在标准数据集进行了初步试验.试验结果显示了提出的算法在分类的精度和速度上都有明显提高. 相似文献
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Production planning in flexible manufacturing systems is concerned with the organization of production in order to satisfy a given master production schedule. The planning problem typically gives rise to several hierarchical subproblems which are then solved sequentially or simultaneously. In this paper, we address one of the subproblems: the part type selection problem. The problem is to determine a subset of part types having production requirements for immediate and simultaneous processing over the upcoming period of the planning horizon, subject to the tool magazine and processing time limitation. Several versions of tabu search (TS) algorithm are proposed for solving the problem. A systematic computational test is conducted to test the performance of the TS algorithms. The best TS algorithm developed is compared to a simulated annealing algorithm. 相似文献
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This paper deals with a bi-criteria single machine scheduling problem with a time-dependent learning effect and release times. The objective is to minimize the weighted sum of the makespan and the total completion time. The problem is NP-hard, thus a mixed integer non-linear programming formulation is presented, and a set of dominance properties are developed. To solve the problem efficiently, a procedure is then proposed by incorporating the dominance properties with an ant colony optimization algorithm. In the proposed algorithm, artificial ants construct solutions as orders of jobs based on the heuristic information as well as pheromone trails. Then, the dominance properties are added to obtain better solutions. To evaluate the algorithm performance, computational experiments are conducted. 相似文献
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近年来世界各地频发灾情疫情等紧急事件,严重影响人民的生活物资保障。在这种情况下,急需建立应急物资中心来缓解燃眉之急。该类问题通常面临资源稀缺并且时间相对紧迫的处境,因此需要在短时间内获得合理的应急设施选址方案来提升服务的质量和效率。本文对应急物资中心选址问题展开研究,提出一种考虑后续运输成本以及有概率发生紧急事件而导致无法正常运送物资的双目标离散选址模型,并为此设计一种二进制多目标蝗虫优化算法。该算法采用模糊关联熵系数来引导迭代更新,同时为其添加外部档案,最优解选择机制和竞争决策机制来提升算法性能。多次数值实验表明该算法的计算效率和求解质量较高,可作为应急物资中心选址问题的一种可行且有效的算法。 相似文献