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1.
1 .INTRODUCTIONConsider thefollowing complexsystemthat comprisesNinterconnected subsystems , the mathematicalmodel of theith subsystemisyi=fi(ci,ui,zi)gi(ci,ui,yi) ≥0ui= Hiywhereci, ui, yiandziare theithsubsystemcontrolinput ,interactioninput ,output and disturbance vec-tor respectively,andfiis the mathematics model oftheithsubsystem.It is assumedthat external distur-bancezwhich affects the systemis constant in theconsidered ti me interval of control and hence will beleft out of the syst…  相似文献   

2.
Structure learning of Bayesian networks is a wellresearched but computationally hard task.For learning Bayesian networks,this paper proposes an improved algorithm based on unconstrained optimization and ant colony optimization(U-ACO-B) to solve the drawbacks of the ant colony optimization(ACO-B).In this algorithm,firstly,an unconstrained optimization problem is solved to obtain an undirected skeleton,and then the ACO algorithm is used to orientate the edges,thus returning the final structure.In the experimental part of the paper,we compare the performance of the proposed algorithm with ACO-B algorithm.The experimental results show that our method is effective and greatly enhance convergence speed than ACO-B algorithm.  相似文献   

3.
针对序列图逆向生成过程中由于动态信息过大造成生成序列图耗时巨大,生成的序列图过于复杂,不利于对目标系统的理解的问题,提出了一种基于关注点的序列图生成算法,对原有算法进行了优化。该算法基于用户在程序理解中关注的方面,包括进程、函数调用层次、某一时间段内的目标程序运行情况、对象在目标系统中扮演的角色等,对收集到的动态信息进行提取,生成基于用户关注点的序列图。使用该算法生成序列图,耗费的时间大大减少,而且生成的序列图便于用户理解目标系统。通过实验验证了这种算法的正确性和有效性。  相似文献   

4.
1 Introduction The earliest network equilibrium model was proposed by Wardrop (1952) for a transportation network Since then, many other equilibrium models have also been proposed in the economics literature (see Nagurney 1993) Until only recently, all these equilibrium models are based on single cost or utility function Recently, equilibrium models based on multicriteria consideration or vector-valued cost functions have been proposed In Chen and Yen (1993), a multicriteria traffic equilibr…  相似文献   

5.
混合递阶遗传算法优化小波神经网络的研究   总被引:3,自引:1,他引:3  
在研究小波神经网络结构及其学习算法的基础上,提出了一种以混合递阶遗传算法优化小波神经网络的新方法,混合递阶遗传算法是递阶遗传算法和多元线性回归的结合。此方法可同时优化小波神经网络的结构及其参数,具有学习速度快,精度高的特点。并与传统的BP算法进行了对比,证明了本算法的有效性。  相似文献   

6.
Surrogate models have shown to be effective in as-sisting evolutionary algorithms (EAs) for solving computationally expensive complex optimization problems. How...  相似文献   

7.
An effective maintenance policy optimization model can reduce maintenance cost and system operation risk. For mission-oriented systems, the degradation process ...  相似文献   

8.
具有多值映射的两级优化问题的广义算法研究   总被引:1,自引:0,他引:1  
两级优化问题是一种非凸非光滑问题,绝大多数问题的求解都是建立在下层有唯一解的基础之上的。而本文针对多值映射,即下层非唯一解的情形,利用隐函数理论,将两级优化问题转化为带有隐函数的非光滑问题,提出求解这类问题的广义算法框架,并证明其收敛性,最后通过实例验证该方法的实用性.  相似文献   

9.
航线网络区间型相对鲁棒优化设计   总被引:1,自引:0,他引:1  
枢纽航线网络的设计参数如果发生变化,最优的航线网络可能也发生变化,此时航线网络缺乏鲁棒性.为增强枢纽航线网络的鲁棒性,引进区间型设计参数情形集,建立了区间型枢纽航线网络相对鲁棒优化模型,修正了最短路算法,并与模拟退火法相结合,设计了模型的混合求解算法.最后,采用航线网络设计的经典数据集进行了算例仿真,结果表明相对于确定性优化设计和离散型鲁棒优化设计的方法,该方法获得的枢纽航线网络具有更强的鲁棒性.  相似文献   

10.
用具有混沌特性的神经网络解任务分配问题   总被引:13,自引:0,他引:13  
利用由一对相互藉合的混沌吸引子作为神经元构造的混沌神经网络来解决任务分配问题。通过与传统Hopfield人工神经网络解决任务分配问题相比,混沌神经网络具有更强的全局搜索能力和寻优能力。实时分布处理系统任务分配问题实例仿结果表明,该网络解任务分配问题有效地避免了Hopfield人工神经网络极易陷入局部极小的缺陷,并具有更高的搜索效率。  相似文献   

11.
求解约束优化问题的改进粒子群算法   总被引:2,自引:0,他引:2  
针对高维复杂约束优化问题,提出了一种基于平滑技术和一维搜索的粒子群算法(NPSO)。该算法使粒子的飞行无记忆性,结合平滑函数和一维搜索重新生成停止进化粒子的位置,增强了在最优点附近的局部搜索能力;定义了不可行度阈值,利用此定义给出了新的粒子比较准则,该准则可以保留一部分性能较优的不可行解微粒,使微粒能快速的找到位于约束边界或附近的最优解;最后,为了扩大粒子的搜索范围,引进柯西变异算子。仿真结果表明,对于复杂约束优化问题,算法寻优性能优良,特别是对于超高维约束优化问题,该算法获得了更高精度的解。  相似文献   

12.
多目标旅行商问题(MOTSP)是经典旅行商问题的扩展,其优化目标包含了距离、成本、收益及风险等多个相互冲突的指标.本文提出了一种基于偏好的Pareto演化算法p-PEA用于建模并求解此NP-hard问题.该优化算法建立在MOTSP的智能体仿真模型之上,从而解决了数学建模不能真实再现实际MOTSP中众多影响因素的问题.通过仿真的方法,算法能够得到MOTSP可行解的各项评价指标值.在此基础士,通过设计演化算法搜索问题的Pareto优化解集.其中,将决策者的决策偏好信息引入到Pareto优化解集的求解过程中,所得结果将更合理.最后,以一个130个城市的旅行商问题为例验证了算法的有效性.  相似文献   

13.
As a new-style stochastic algorithm, the electromagnetism-like mechanism(EM) method gains more and more attention from many researchers in recent years. A novel model based on EM(NMEM) for multiobjective optimization problems is proposed, which regards the charge of all particles as the constraints in the current population and the measure of the uniformity of non-dominated solutions as the objective function. The charge of the particle is evaluated based on the dominated concept, and its magnitude determines the direction of a force between two particles. Numerical studies are carried out on six complex test functions and the experimental results demonstrate that the proposed NMEM algorithm is a very robust method for solving the multiobjective optimization problems.  相似文献   

14.
针对狼群算法(wolf pack algorithm,WPA)求解大规模问题时存在解精度低、收敛速度慢和易陷入局部最优的缺点,提出了一种改进的狼群算法(improved wolf pack algorithm,IWPA).采用深度神经网络进行初始化狼群个体提高种群多样性;借助遗传算法挑选首狼提高算法寻优能力;设计距离优化因子以协同狼群算法个体的探索和开发能力;构建尺度系数改进围捕行为避免算法陷入局部最优,减少运行时间.选取18个大规模(100维,200维,500维和1000维)标准测试函数进行性能对比,结果表明,IWPA算法在求解精度和收敛速度上优于其他对比算法.  相似文献   

15.
Adaptive immune evolutionary algorithm is proposed based on the principle of adaptive immune response. Two new algorithm parameters of expansion radius and mutation radius are defined to construct a small neighborhood and a large neighborhood, then expansion and mutation operations are designed to search the local and global regions of solution space simultaneously by using the two neighborhoods, thus, two-level neighborhood search mechanism is realized. The degree of the diversity in the population is described with the average Euclideandistance among all individuals, and it is used to adjust algorithm parameters adaptively to accelerate convergence and avoid getting stuck at local optima. The algorithm is proved to be convergent and its optimization principle is analyzed. The experiment results of multi-modal function optimization show that the algorithm is effective.  相似文献   

16.
The purpose of this paper is to present a general iterative scheme as below:
and to prove that, if {α n } and {r n } satisfy appropriate conditions, then iteration sequences {x n } and {u n } converge strongly to a common element of the set of solutions of an equilibrium problem and the set of fixed points of a nonexpansive mapping and the set of solution of a variational inequality, too. Furthermore, by using the above result, we can also obtain an iterative algorithm for solution of an optimization problem , where h(x) is a convex and lower semicontinuous functional defined on a closed convex subset C of a Hilbert space H. The results presented in this paper extend, generalize and improve the results of Combettes and Hirstoaga, Wittmann, S.Takahashi, Giuseppe Marino, Hong-Kun Xu, and some others. This research is supported by the National Natural Science Foundation of China under Grant No. 10771050.  相似文献   

17.
冯博 《系统工程学报》2012,27(2):177-184
为解决具有多个需求节点和多个服务中心的服务网络,如何在预算约束条件下设计与优化服务网络的服务中心配置,使得服务网络运营的总效率最高的决策问题,本文对多个服务中心的服务网络优化问题进行了提炼和描述,并构建了服务网络设计的优化模型,同时证明了该服务网络优化问题是一个NP-完全问题;进一步,针对优化模型的特点,设计了求解模型的混合拆分遗传算法,进行了大规模仿真实验并与传统的多目标遗传算法进行了比较,结果表明本文给出的算法具有较好的求解效率和效果;最后,通过例子说明了本文提出方法的潜在应用价值.  相似文献   

18.
For large multinational companies, the complex production process of their finished goods usually contains plenty of stages, which constitute a production flow network. Each production stage in the production flow network can be undertaken by one or more suppliers. This study proposes a stochastic programming model for the production flow network oriented supply chain network design problem, which optimizes the decision of allocating stages to suppliers with the objective of minimizing the total expected costs of production and transportation among suppliers under uncertain demands of customers. A local branching based solution method is developed to solve the model. A case study on applying this model to a large automobile company is performed. In addition, some numerical experiments are conducted to validate the effectiveness of the proposed model and the efficiency of the proposed solution method.  相似文献   

19.
Creative telescoping is the method of choice for obtaining information about definite sums or integrals. It has been intensively studied since the early 1990s, and can now be considered as a classical technique in computer algebra. At the same time, it is still a subject of ongoing research. This paper presents a selection of open problems in this context. The authors would be curious to hear about any substantial progress on any of these problems.  相似文献   

20.
In this paper,by using Ljusternik’s theorem and the open mapping theorem of convex process,the author gives necessary conditions for the efficient solution to the vector optimization problems without requiring that the ordering cone in the objective space has a nonempty interior.  相似文献   

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