共查询到19条相似文献,搜索用时 387 毫秒
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一种求解双目标flow shop排序问题的进化算法 总被引:1,自引:0,他引:1
提出一种求解双目标flow shop排序的递进多目标进化算法.算法采用改进的精英复制策略,在实现精英保留的前提下降低了计算复杂性;通过递进进化模式增加群体多样性,改善了算法收敛性;通过群体进化过程中对非劣解集进行竞争型可变邻域启发式搜索,增强了算法局部搜索性能.采用新算法和参照算法NSGA-II对31个标准双目标flow shop算例进行优化.研究结果表明,新算法在所有算例的求解中均获得了优于NSGA-II的非劣解集,验证了算法的有效性. 相似文献
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本文针对模糊C均值聚类在大数据量时收敛较慢以及不能对多种数据结构有效聚类的缺点,结合PIM算法与核方法提出了一种新的高效聚类算法———KPIM算法,并从理论上证明了该算法的收敛性.最后利用标准实验数据IRIS数据集测试,结果表明KPIM算法在保证收敛速度的同时,聚类效果更有效. 相似文献
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为了对客户流失风险分析过程中的大量的冗余特征进行约简或压缩,本文利用粗集理论中的特征约简方法来研究客户流失风险分析,提出了一种基于粗集的客户流失风险的分析方法.通过一个客户流失风险的分析实例对该算法进行了检验,实验结果表明,在保证分类质量基本不变的情况下,该算法可以查找出对分类起主要作用的特征,从而达到了特征约简的目的,成功地将粗集理论应用到客户流失风险的分析和预警中,为客户流失风险的分析和预警提供了一条新的研究思路和方法. 相似文献
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基于PSO和SVM的上市公司财务危机预警模型 总被引:1,自引:0,他引:1
提出了一种将经过改进的离散粒子群(PSO)算法和支持向量机(SVM)相结合的算法,以选择最优的指标集并用于财务危机预警。将此算法应用于上市公司的数据,检验模型提前3年的预警效果,最后与常见的主成分分析方法与SVM相结合的模型进行对比,结果证明了PSO-SVM模型的合理性和优越性。 相似文献
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《Omega》2005,33(1):65-71
The paper presents a new graph representation, the graph matrix, which combines the adjacency matrix with the linked lists allowing for the fastest possible access to different types of information on a graph. This is increasingly important for a high search performance, for instance, for rapidly extracting information from the link structure in a hub and authority graph of the World-Wide-Web. A very recent application for the proposed data structure arises from categorical data clustering defining proximity and similarity of data through their patterns of co-occurrence. 相似文献
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We describe a two-phase algorithm for MAX-SAT and weighted MAX-SAT problems. In the first phase, we use the GSAT heuristic to find a good solution to the problem. In the second phase, we use an enumeration procedure based on the Davis-Putnam-Loveland algorithm, to find a provably optimal solution. The first heuristic stage improves the performance of the algorithm by obtaining an upper bound on the minimum number of unsatisfied clauses that can be used in pruning branches of the search tree.We compare our algorithm with an integer programming branch-and-cut algorithm. Our implementation of the two-phase algorithm is faster than the integer programming approach on many problems. However, the integer programming approach is more effective than the two-phase algorithm on some classes of problems, including MAX-2-SAT problems. 相似文献
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考虑到无人仓系统补货阶段货架上只有部分空余储位的特点,研究了补货商品储位分配问题的优化模型与算法。以同一货架上存放的商品之间关联度之和最大化为目标建立了混合整数规划模型;结合贪婪算法和邻域搜索算法设计了求解模型的两阶段方法。第一阶段利用贪婪算法求初始可行解;第二阶段利用邻域搜索算法对初始可行解进行优化。利用一个具体算例验证了邻域搜索算法的优化效果,结果显示,通过邻域搜索算法对初始可行解的优化,可以使目标函数值至少提升27%。进一步利用多个小规模算例分析了两阶段算法的近似比和求解速度,验证了算法的快速有效性。本文的研究结果不仅解决了货架初始状态非空情况下的储位分配问题,同样适合解决货架初始状态为空的情况,因此更加符合实际场景,可以作为无人仓管理信息系统的核心模型和算法。 相似文献
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Young-Soo Myung 《生产规划与管理》2013,24(3):339-342
Lee et al. (Lee, K., Chang, S.Y., and Hong, Y., 2004. Continuous slab caster scheduling and interval graphs. Production Planning & Control, 13 (5), 495–501) have introduced a slab caster scheduling problem and developed an optimal algorithm. Their algorithm is efficient but an offline algorithm that we need the information on all the customer orders a priori to implement. In this article, we propose an online algorithm that we can implement without knowledge of the orders yet to arrive. We show that the offline version of our new algorithm also provides an optimal solution and the online version has the worst case performance ratio of 3. We also give a short proof on the correctness of Lee et al.'s algorithm. 相似文献
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The hierarchical model for load balancing on two machines 总被引:1,自引:1,他引:0
Following previous work, we consider the hierarchical load balancing model on two machines of possibly different speeds. We
first focus on maximizing the minimum machine load and show that no competitive algorithm exists for this problem. We overcome
this barrier in two ways, both related to previously known models. The first one is fractional assignment, where each job
can be arbitrarily split between the machines. The second one is a semi-online model where the sum of jobs is known in advance.
We design algorithms of best possible competitive ratios for both these cases. Furthermore, we show that the combination of
the two models leads to the existence of an optimal algorithm (i.e., an algorithm of competitive ratio 1). This algorithm
is clearly optimal for the makespan minimization problem as well. For the latter problem, we consider the fractional assignment
model and design an algorithm of best possible competitive ratio for it.
This work was submitted as the M.Sc. thesis of the first author. 相似文献
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This paper presents a multi-neighborhood based path relinking algorithm (MN-PR) for solving the two-sided assembly line balancing problem. By incorporating an effective local search into a path relinking framework, the proposed MN-PR algorithm integrates a number of distinguishing features, such as a multi-neighborhood based local search procedure, a dedicated path relinking operator to generate new solutions and a strategy to fix an infeasible solution generated by the path relinking procedure to a feasible one. Our proposed MN-PR algorithm is tested on a set of totally 45 public instances widely used in the literature. Comparisons with other reference algorithms show the efficacy of the proposed algorithm in terms of the solution quality. Particularly, the proposed MN-PR algorithm is able to improve the best upper bounds for one instance with 65 tasks and 326 cycle time. This paper also presents an analysis to show the significance of the main components of the proposed algorithm. 相似文献
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This paper considers the problem of non-preemptive scheduling n tasks on m identical parallel processors to minimize makespan for simultaneous arrivals. Based on a pairwise interchange method, an efficient algorithm ispresented which is able to give a near-optimal schedule in a short time through suitable pairwise interchange between tasks, after an initial solution is constructed. The behaviour of the algorithm is discussed. Testing results prove its high performance in comparison with available simple heuristic procedures. Finally, the algorithm is generalized for the problems of non-identical processors and non-simultaneous arrivals. 相似文献