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1.
组合优化调度问题求解方法 总被引:5,自引:0,他引:5
1.引言优化是指一个从一组解中选取出最优解或最适应解的过程。优化方法涉及的工程领域很广,问题种类与性质繁多。归纳而言,最优化问题可分为函数优化问题和组合优化问题。其中函数优化的对象是一定区间内的连续变量,而组合优化的对象则是解空间中的离散状态。函数优化问题通常可描述为:令S为R~n上的有界子集(即变量的定义域),f:S→R为n维 相似文献
2.
Project Scheduling问题和Job—Shop问题的神经网络解 总被引:1,自引:0,他引:1
ProjectScheduling问题和Job-Shop问题是著名的NP难题。本文用神经网络方法去解这两个问题,软件模拟结果是令人满意的。这种方法也为解一大类组合优化问题提供了一个新的途径。 相似文献
3.
冯光毅 《计算机光盘软件与应用》2013,(24):99-100
贪婪算法作为一种求最优解问题的方法,具有简便、迅捷的特点,然而贪婪算法因其基于局部求最优解的特点,决定了其在很大程度上无法得到问题的最优解。本文通过对[0-1背包问题]以及部件加工问题的分析,阐述了贪婪算法的应用以及贪婪算法存在的局限性,进而引出贪婪算法的优化方案——k阶优化方法,进一步对求最优解问题进行完善和归纳。 相似文献
4.
可行解优先蚁群算法对车辆路径问题的求解 总被引:2,自引:2,他引:0
针对车辆路径问题,给出了一种利用蚁群算法求解该问题的新方法。借鉴K-TSP问题的求解方法,优先构造可行解,通过对较优解路径上信息素的增强,最终得到问题的最优解或较优解。实验结果表明,用本方法求解车辆路径问题,简化了求解过程,缩短了求解时间,解决了无可行解的问题。 相似文献
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主要研究了用遗传算法求解TSP问题。阐述了简单遗传算法的设计方法、基本原理和基本步骤。描述了简单遗传算法在TSP问题中的应用现状。根据种群个体的多样性和分布情况,提出了判定遗传算法的截止代数。简单遗传算法具有易于陷入局部最优解、收敛速度慢的特点,针对这些特点,通过改进交叉算子,加入初始化启发信息,提高了遗传算法解的精度和收敛性。 相似文献
7.
加群Zp+上离散对数问题在公钥密码系统分析中具有非常广泛的应用.研究一种加群Zp+上离散对数问题的DNA计算算法.算法主要由解空间生成器、并行乘法器、并行加法器、解转换器及解搜索器组成.其中解空间生成器借鉴传统计算机中3表算法的思想,将解空间的生成分为3个部分来完成,极大减少了非法解的搜索空间.本算法的生物操作时间复杂度为O(k2),需要O(1)个试管数、O(2k)条DNA链,最长DNA链长为O(k2)(其中k为加群上离散对数问题群阶p的二进制编码位数).最后,通过DNA计算通用的试验方法对算法进行了仿真,验证了算法的可行性和有效性. 相似文献
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论文给出了基于可满足解空间的最小顶点覆盖问题的DNA算法,该算法直接生成可满足解空间,无须在全体解空间中进行各种过滤过程。在对图中的顶点进行适当的编码后,使用常规的生物操作完成可满足解空间的产生及最终解的分离。最后指出了该算法的优点、存在问题及下一步的研究方向。 相似文献
10.
加群Zp+上离散对数问题在公钥密码系统分析中具有非常广泛的应用。研究一种加群Zp+上离散对数问题的DNA计算算法。算法主要由解空间生成器、并行乘法器、并行加法器、解转换器及解搜索器组成。其中解空间生成器借鉴传统计算机中3表算法的思想,将解空间的生成分为3个部分来完成,极大减少了非法解的搜索空间。本算法的生物操作时间复杂度为O(k2),需要O(1)个试管数、O(2k)条DNA链,最长DNA链长为O(k2)(其中k为加群上离散对数问题群阶p的二进制编码位数)。最后,通过DNA计算通用的试验方法对算法进行了仿真,验证了算法的可行性和有效性。 相似文献
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Kensuke Yokoi 《Journal of scientific computing》2008,35(2-3):372-396
We propose a simple and practical numerical method for free surface flows. The method is based various methods, the level set method of an interface capturing method, the THINC/WLIC (tangent of hyperbola for interface capturing/weighed line interface calculation) method of an interface tracking method, the CIP-CSL (constrained interpolation profile conservative semi-Lagrangian) method of a conservation equation solver, VSIAM3 (volume/surface integrated average based multi-moment method) of a fluid solver and the CSF (continuum surface force) model of a surface force model. The level set method and the THINC/WLIC method are combined by using a CLSVOF (coupled level set and volume-of-fluid) framework. The method is applied to Rayleigh-Taylor instability with surface tension force and droplet impact on a thin liquid layer (milk crown). 相似文献
13.
In this paper the development and assessment of a new formative evaluation method called the problem identification picture
cards (PIPC) method is described. This method enables young children to express both usability and fun problems while playing
a computer game. The method combines the traditional thinking-aloud method with picture cards that children can place in a
box to indicate that there is a certain type of problem. An experiment to assess this method shows that children may express
more problems (verbally, or with a picture card, or with a combination of a picture card and a verbalisation) with the PIPC
method than without this method (in which they can only indicate problems verbally). Children in the experiment did not just
replace verbalisations by using the provided picture cards and some children preferred to use the PIPC method during the test
instead of the standard thinking-aloud method. The PIPC method or some aspects of the method could be a good instrument to
increase the amount of information expressed by young children during an evaluation. 相似文献
14.
L. Zhang 《Computers & Structures》1982,15(5):543-547
The paper describes a Modified Secant Newton method (MSN) which is derived from the variable metric method. The present procedure differs from the Secant Newton method (SN) in that in the MSN method the iterative displacement change involves only a scalar multiple of the usual unaccelerated change. Both the MSN method and the SN method are based on a Secant approach, but the MSN method leads to a reduction in the required number of iterations compared to the SN method. Two numerical examples involving elasto-plastic behaviour are presented. 相似文献
15.
医学图像表面重建是协助医生对人体内部病变做出准确诊断的重要手段,而重建的速度直接影响医生的工作效率。为加快重建的速度,提出一种基于逆向Shear-Warp和边缘体素的快速重建算法。采取逆向Shear-Warp方法,减少了不必要的数据处理;通过在完全相反的两个方向上提取边缘体数据,得到全部的表面体素,重复利用这些体数据,而不必每次重新遍历整个数据场,提高了边缘体素的利用效率,达到了快速重建的目的。 相似文献
16.
提出Vague值向Fuzzy值转化的实用方法的定义。针对文献[6]中的一个Vague值向Fuzzy值转化的均值修正法,提出了加权均值修正法,并证明了这种方法同样是Vague值向Fuzzy转化的一种非常实用的方法。 相似文献
17.
基于遗传算法的K均值聚类分析 总被引:11,自引:0,他引:11
1 前言聚类分析就是将数据对象分组成为多个类或簇,在同一个簇中的对象之间具有较高的相似度,而不同的簇中的对象差别较大。聚类分析目前应用广泛,已经成为数据挖掘主要的研究领域。通过聚类,人们能够识别密集的和稀疏的区域,从而发现数据的整体分布模式,还能找到数据间的有趣的相互关系。关于聚类分析目前已经有K均值,CURE等很多算法, 相似文献
18.
Fredrik Karlsson 《欧洲信息系统杂志》2013,22(6):690-710
Organizations that implement a company-wide method to standardize the way that systems development is carried out still have a need to adapt this method to specific projects. When adapting this method the end results should align with the basic philosophy of the original method. To this end, goal-driven situational method engineering has been proposed. However, there are no longitudinal studies on systems developers’ use of such approaches and their intentions to balance their need of adaptation with the basic philosophy of the original method. This paper explores how goal-driven method configuration has been used by two project teams in six successive systems development projects, with the intention to balance the goals and values of a specific method with the systems developers’ need for method adaptation. We do that through the use of method rationality resonance theory. Through content examples of method configurations, we report on (a) lessons learned from the project teams’ work on balancing the goals of the company-wide method with their needs and (b) theoretical development of the method rationality resonance theory. 相似文献
19.
An Yong Lee Jongguk Yim Youngjin Choi 《International Journal of Control, Automation and Systems》2014,12(5):1102-1109
This paper presents a scaled Jacobian transpose based control method for robotic manipulators as a modification of a conventional Jacobian transpose based method. The proposed method has several advantages such as it shows faster convergence and better tracking performance than the conventional method, furthermore, it does not have any singularity problem similar to the conventional method. The scaled Jacobian transpose is obtained by collecting each pseudoinverse of the column vector of the Jacobian matrix. The proposed method performs a given task well under singular configurations while minimizing the task error. Finally, a few comparative studies with the conventional method are provided to show the effectiveness of the proposed method through simulations. 相似文献
20.
在动态环境中移动机器人导航和避碰的一种新方法 总被引:17,自引:0,他引:17
本文提出了基于超声传感器的信息,将改进的栅格
和回归预测法结合起来,应用于具有静态和动态障碍物的动态环境中,移动机器人THMR-Ⅱ
的导航和避碰的一种新方法.对栅格法的改进就是以障碍物为单位记录信息量,结果比原来
以栅格为单位记录的信息量少得多,克服了栅格法中存在环境信息存储量大的问题,提高了
实时性.对回归预测法也作了改进,并把它们结合起来,在求得最佳候选扇区后,使移动机
器人躲避了静态和动态障碍物,实现了导航,最终到达目标.通过三种仿真实验,结果表明
作者提出的方法是正确和有效的. 相似文献