首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
完全分层多目标规划的基线算法   总被引:6,自引:1,他引:5  
本文采用基线算法求解完全分层多目标规划问题。给出了简单完全分层多目标规划基线算法的求解步骤,并对其进行了修正,从而得到完全分层多目标规划的宽容基线算法。并给出了两个计算实例。  相似文献   

2.
基于改进基线算法的线性规划灵敏度问题研究   总被引:1,自引:0,他引:1  
针对基线算法由于计算方面的无记忆性而在线性规划灵敏度方面的难实现问题,提出了改进的基线算法,并分别讨论了在价值系数C、技术系数矩阵A及资源向量b等各种情况发生变化的条件下,如何采用改进的基线算法进行灵敏度分析,从而能够简便、快捷的获得新的最优解.最后通过实例进行了说明.  相似文献   

3.
本文对有界变量线性规划的算法进行了研究,得到了一种解此问题的新算法。文中根据基线算法的算法原理,通过对BL表的旋转,在各变量满足界约束的条件下,使目标函数值不断增大,直至得到有界硬上界,从而得到问题的最优解。文中给出了有界变量线性规划基线算法的计算步骤,并给出了一个例子。与单纯形法相比,采用基线算法解有界变量线性规划操作更简单。迭代次数少,解题速度更快。  相似文献   

4.
粒子群算法原理简单、参数少、易于实现,但有时容易陷入局部最优解,收敛速度慢.本文在粒子群算法理论研究的基础上,对算法的初始值选取、惯性权重取值、算法结构进行了改进:首先采用线性惯性递减权重调整,平衡全局搜索和局部搜索的能力;然后通过logistic映射将混沌状态引入到优化变量中,增强搜索空间的遍历性;最后引入遗传算法中的选择、交叉、变异保持了种群的多样性,使其具有不易陷入局部最优的能力.采用六种典型的测试函数,对惯性权重和算法进行了测试和对比分析.结果表明,算法在收敛速度和精度上都有所提高.  相似文献   

5.
GA-BP嵌套算法的理论及应用   总被引:2,自引:0,他引:2  
分析了BP算法、遗传算法以及GA-BP-APARTING算法的特点,提出了GA-BP-NESTING算法.在人工神经网络的在线学习和离线学习方式下,分别对BP算法、GA算法、GA-BP-APARTING算法和GA-BP-NESTING算法进行了比较研究,研究发现:第一,网络初始权值的赋值对人工神经网络训练影响很大;第二,离线学习方式下GA-BP-NESTING算法效果最佳.  相似文献   

6.
针对蝙蝠算法在搜索评分阶段易陷入局部最优且收敛精度低,以及基于蝙蝠算法的贝叶斯网络结构学习不完善等缺点,将模拟退火算法的思想引入到蝙蝠算法中,并对某些蝙蝠个体进行高斯扰动,提出了一种改进蝙蝠算法的贝叶斯网络结构混合学习算法.混合算法首先应用最大最小父子节点集合算法(Max-min parents and children,MMPC)来构建初始无向网络的框架,然后利用改进的蝙蝠算法进行评分搜索并确定边的方向.最后把应用本算法学习的ALARM网,和蚁群算法(MMACO)、蜂群算法(MMABC)进行比较,结果表明本混合算法具有较强的学习能力和更好的收敛速度,并且能够得到与真实网络更匹配的贝叶斯网络.  相似文献   

7.
针对传统MUSIC算法运算量过大以及低信噪比下分辨率差的问题,提出将改进人工鱼群算法与MUSIC的谱峰搜索相结合,利用鱼群觅食和追逐来对解空间进行高效搜索,从而保证算法收敛的快速性和全局性.聚群的存在促使少量陷于局部最优解的人工鱼向着全局最优解的方向靠拢,提高了鱼群对不利环境的自适应性,也增强了算法的稳定性.与此同时,改进人工鱼群算法在一定程度上加快了后期收敛速度,提高了算法的估计性能.实验结果表明在低信噪比时方法相较于MUSIC而言具有更好的估计性能,并且大大减少了运算量,保证了算法的实时性.  相似文献   

8.
近来,哈密尔顿偏微分方程多辛算法的研究越来越热门.多辛算法已经成为保结构算法的一个重要分支.对哈密尔顿偏微分方程多辛算法的发展进行了综述,其中包括其基本概念、主要结果和一些应用.此外,文章还部分阐述了多辛算法概念的推广和延伸.  相似文献   

9.
模糊C均值算法的改进   总被引:13,自引:0,他引:13  
模糊聚类分析方法具有较强的实用性,但传统的模糊C均值算法对数据集进行分类时有均分的趋势,对于数据集中各类样本数目相差较大的情况,其聚类结果不是很理想.因此,本文对FCM算法进行了改进,使之不但能够达到更好的分类效果,同时也更加适用于样本分类不均衡的聚类问题.文中还结合具体算例进行了聚类分析,得到了理想的分类效果.  相似文献   

10.
为了提高求解鞍点问题的迭代算法的速度,通过设置合适的加速变量,对修正超松弛迭代算法(简记作MSOR-like算法)和广义对称超松弛迭代算法(简记作GSSOR-like算法)进行了修正,给出了修正对称超松弛迭代算法,即MSSOR-like (modified symmetric successiveover-relaxation)算法,并研究了该算法收敛的充分必要条件.最后,通过数值例子表明,选择合适的参数后,新算法的迭代速度和迭代次数均优于MSOR-like (modified successive overrelaxation)和GSSOR-like (generalized symmetric successive over-relaxation)算法,因此,它是一种较好的解决鞍点问题的算法.  相似文献   

11.
用列队竞争算法解旅行商问题   总被引:10,自引:1,他引:9  
给出了列队竞争算法解组合优化问题的框架和确定变异邻域的两条原则。用列队竞争算法解旅行商问题获得了满意的结果,显示出列队竞争算法良好的全局搜索性能。  相似文献   

12.
A theoretical comparison between the simplex method (SM) and the basic line search method (BLSA) is presented. The explicit formulae for the upper and lower bounds in the BLSA are provided using SM. Further, it is shown that both methods are operationally equivalent.  相似文献   

13.
本文就指派问题匈牙利解法中的一些方法提出两个注记,且为此提供一个较为简单的解法。  相似文献   

14.
This paper proposes a line search technique to satisfy a relaxed form of the strong Wolfe conditions in order to guarantee the descent condition at each iteration of the Polak-Ribière-Polyak conjugate gradient algorithm. It is proved that this line search algorithm preserves the usual convergence properties of any descent algorithm. In particular, it is shown that the Zoutendijk condition holds under mild assumptions. It is also proved that the resulting conjugate gradient algorithm is convergent under a strong convexity assumption. For the nonconvex case, a globally convergent modification is proposed. Numerical tests are presented. This paper is based on an earlier work presented at the International Symposium on Mathematical Programming in Lausanne in 1997. The author thanks J. C. Gilbert for his advice and M. Albaali for some recent discussions which motivated him to write this paper. Special thanks to G. Liu, J. Nocedal, and R. Waltz for the availability of the software CG+ and to one of the referees who indicated to him the paper of Grippo and Lucidi (Ref. 1).  相似文献   

15.
Disassembly activities take place in various recovery operations including remanufacturing, recycling and disposal. The disassembly line is the best choice for automated disassembly of returned products. It is therefore important that the disassembly line be designed and balanced so that it works as efficiently as possible. The disassembly line balancing problem seeks a sequence which: is feasible, minimizes workstations, and ensures similar idle times, as well as other end-of-life specific concerns. However finding the optimal balance is computationally intensive with exhaustive search quickly becoming prohibitively large even for relatively small products. In this paper the problem is mathematically defined and proven NP-complete. Additionally, a new formula for quantifying the level of balancing is proposed. A first-ever set of a priori instances to be used in the evaluation of any disassembly line balancing solution technique is then developed. Finally, a genetic algorithm is presented for obtaining optimal or near-optimal solutions for disassembly line balancing problems and examples are presented to illustrate implementation of the methodology.  相似文献   

16.
The Dual Active Set Algorithm (DASA), presented in Hager, Advances in Optimization and Parallel Computing, P.M. Pardalos (Ed.), North Holland: Amsterdam, 1992, pp. 137–142, for strictly convex optimization problems, is extended to handle linear programming problems. Line search versions of both the DASA and the LPDASA are given.  相似文献   

17.
Two parallel deterministic direct search algorithms are combined to find improved parameters for a system of differential equations designed to simulate the cell cycle of budding yeast. Comparing the model simulation results to experimental data is difficult because most of the experimental data is qualitative rather than quantitative. An algorithm to convert simulation results to mutant phenotypes is presented. Vectors of the 143 parameters defining the differential equation model are rated by a discontinuous objective function. Parallel results on a 2200 processor supercomputer are presented for a global optimization algorithm, DIRECT, a local optimization algorithm, MADS, and a hybrid of the two.  相似文献   

18.
Inexact spectral projected gradient methods on convex sets   总被引:9,自引:0,他引:9  
A new method is introduced for large-scale convex constrainedoptimization. The general model algorithm involves, at eachiteration, the approximate minimization of a convex quadraticon the feasible set of the original problem and global convergenceis obtained by means of nonmonotone line searches. A specificalgorithm, the Inexact Spectral Projected Gradient method (ISPG),is implemented using inexact projections computed by Dykstra'salternating projection method and generates interior iterates.The ISPG method is a generalization of the Spectral ProjectedGradient method (SPG), but can be used when projections aredifficult to compute. Numerical results for constrained least-squaresrectangular matrix problems are presented.  相似文献   

19.
列车开行方案的设计是铁路旅客运输组织规划中的一个重要环节。本文首先给出了一个综合考虑铁路旅客运输的经济效益和公共服务性的优化模型,以铁路旅客运输的公共效益最大化为目标,对整个铁路客运网络上不同始发-终到和不同停站方式的列车开行方案进行优化。然后提出了一个求解此模型的启发式列生成算法,该算法与标准列生成算法相比,可以减少迭代次数并缩短收敛时间。最后给出一组利用随机生成的网络和需求进行求解的算例,验证本算法可以在较短时间内求解较大规模的铁路网络列车开行方案优化问题,并能有效缩小问题规模。  相似文献   

20.
一类带线搜索的非单调信赖域算法   总被引:15,自引:0,他引:15  
本文对于无约束最优化问题提出了一类新的非单调信赖域算法.与通常的非单调信赖域算法不同,当试探步不成功时,并不重解信赖域子问题,而采用非单调线搜索,从而减小了计算量.在适当的条件下,证明了此算法的全局收敛性.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号