共查询到20条相似文献,搜索用时 15 毫秒
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基于多种群进化小生境遗传算法的神经网络进化设计方法研究 总被引:17,自引:2,他引:17
针对神经网络进化设计问题中棋型解基因编码与棋型解空间的特点,提出了多种群进化小生境遗传算法。该神经网络进化楚棋方法设计简单、通用,棋型性能评价全面合理,全局搜索效率高,电力负荷预测支持系统的实际应用效果表明此方法是有效的,具有一定的应用推广价值。 相似文献
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基于遗传算法和强化学习的贝叶斯网络结构学习算法 总被引:1,自引:0,他引:1
遗传算法是基于自然界中生物遗传规律的适应性原则对问题解空间进行搜寻和最优化的方法。贝叶斯网络是对不确定性知识进行建模、推理的主要方法,Bayesian网中的学习问题(参数学习与结构学习)是个NP-hard问题。强化学习是利用新顺序数据来更新学习结果的在线学习方法。介绍了利用强化学习指导遗传算法,实现对贝叶斯网结构进行有效学习。 相似文献
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本体作为语义网的基石,发挥着越来越重要的作用。本体进化的目的在于动态调整本体以适应环境的变化。从基于领域本体的用户日志出发,使用Aporior算法挖掘用户操作的频繁项集和频繁路径。通过对频繁项集和频繁路径的分析,得到了本体进化的辅助建议,并在实验中对该方法进行了实现和测试,实验结果证明该方法能有效地实现本体进化。 相似文献
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为了更好地界定本体中的概念,提出一种基于遗传算法(Genetic Algorithm,GA)的本体概念分类规则的学习方法.从已有的本体库中获取实例作为训练样本,通过该算法寻找一组与数据样本集一致的规则.以一组规则集作为遗传算法的个体,即优化的目标,同时考虑到规则集的覆盖性、一致性、简洁性和多样性4个方面建立适应值函数,优化得到一组能够分类概念的规则集合.进而这组规则集可用于指导和丰富本体知识,例如当本体中引入新的实例时,可以通过此概念分类规则集确定实例所属的概念.对已有本体学习后的实验结果表明该算法收敛性很好,而且能获得较好的规则集. 相似文献
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支持Internet上个性化信息重组与发布的Web挖掘关键技术的研究 总被引:1,自引:0,他引:1
Internet上个性化信息的重组与发布是Web个性化技术的一个重要组成部分,这一领域目前存在的主要问题是:并非没有信息重组和发布的工具,而是缺乏能够使这类工具高效工作的支持技术。本文提出一种将流数据处理技术引入Web点击流、IP地址流及页面文本流挖掘和分析过程,研究基于Web数据流挖掘的用户行为和需求分析方法;将本体和领域知识引入Web内容挖掘过程,研究领域知识指导下的Web内容挖掘方法;将基于Web数据流挖掘的用户行为和需求分析与领域知识指导下的Web内容挖掘相结合,研究Internet上Web信息模式和Web用户模型及其相互关系的建立;将上述研究成果应用于实际,以期达到高效地支持Internet上满足用户个性化要求的信息重组与发布的目的。 相似文献
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C. Gil J. Ortega A. F. Díaz M. D. G. Montoya 《Future Generation Computer Systems》1998,14(5-6):439-451
In this paper simulated annealing and genetic algorithms are applied to the graph partitioning problem. These techniques mimic processes in statistical mechanics and biology, respectively, and are the most popular meta-heuristics or general-purpose optimization strategies. A hybrid algorithm for circuit partitioning, which uses tabu search to improve the simulated annealing meta-heuristics, is also proposed and compared with pure tabu search and simulated annealing algorithms, and also with a genetic algorithm. The solutions obtained are compared and evaluated by including the hybrid partitioning algorithm in a parallel test generator which is used to determine the test patterns for the circuits of the frequently used ISCAS benchmark set. 相似文献
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Xiao-Bing Hu Shu-Fan Wu Ju Jiang 《Engineering Applications of Artificial Intelligence》2004,17(8):897-907
Free flight (FF) is the ideal strategy of current investigations on air traffic management systems, where an on-line flight path optimization algorithm is of top importance. This paper proposes an innovative algorithm with potential real-time properties for FF path optimization, by using an improved genetic algorithm (GA). Two kinds of mathematical models for the on-line flight path optimization problem are proposed to cover the near and far future applications. Several improvements are introduced to the GA to speed up its convergence as well as to improve performance. Simulation results show that the new algorithm is effective and has potential to solve the on-line FF path optimization problem in real time. 相似文献
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Chang-Yu Hung Robert T. Sumichrast Evelyn C. Brown 《Computers & Industrial Engineering》2003,44(4):651-672
Construction firms specializing in large commercial buildings often purchase large steel plates, cut them into pieces and then weld the pieces into H-beams and other construction components. We formalize the material ordering and cutting problem faced by this industry and propose a grouping genetic algorithm, called CPGEA, for efficiently controlling the relevant costs. We test the quality of CPGEA in various ways. Three sets of simulated problems with known optimal solutions are solved using CPGEA, and the gap between its solutions and optimal solutions is measured. The same problem sets are also solved with an expert system and a multi-start greedy heuristic. CPGEA solutions are found to be consistently lower cost than the competing methods. The difference in solution quality is most pronounced for difficult problems requiring multiple identical plates in the optimal solution. CPGEA is also tested using data from actual construction projects of a company faced with this problem. Since an optimal solution for the problems is not available, a lower bound is created. For the historical problems tested, the average percent difference between CPGEA solutions and the lower bound is 0.67%. To put this performance in context, the results of solving these problems with an expert system and using experienced engineers is also reported. Of these three methods, CPGEA achieves the best performance and the human experts the worst performance. 相似文献
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An impulse control approach to spacecraft autonomous rendezvous based on genetic algorithms 总被引:1,自引:0,他引:1
Xuebo YangAuthor Vitae Jinyong Yu Author VitaeHuijun Gao Author Vitae 《Neurocomputing》2012,77(1):189-196
This paper proposes a novel approach to spacecraft impulse autonomous rendezvous by using genetic algorithms. Based on the Clohessy-Wiltshire (C-W) equations, the whole rendezvous process is described as a switching system composed of closed-loop system and open-loop system, which correspond to the impulse action phase and free motion phase during the rendezvous process. Based on Lyapunov theory, the autonomous rendezvous problem is regarded as an asymptotic stabilization problem. By introducing two virtual energy functions, the stability of the switching system is analyzed, and the duration of the impulse action and the thrust limitation are considered synthetically. Then, a state-feedback controller design method is proposed, and an approach based on linear matrix inequality and genetic algorithm (GA) is proposed to solve the controller design problem and the calculation steps are presented. With the designed controller, the impulse thrust which satisfies the given thrust constraint is determined according to the real-time relative state between two spacecraft at the impulse instant, and the impulse duration is kept as short as possible. The effectiveness of the proposed approach is illustrated by simulation examples. 相似文献
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Saving-based algorithms are commonly used as inner mechanisms of efficient heuristic construction procedures. We present a general mechanism for enhancing the effectiveness of such heuristics based on a two-level genetic algorithm. The higher-level algorithm searches in the space of possible merge lists which are then used by the lower-level saving-based algorithm to build the solution. We describe the general framework and we illustrate its application to three hard combinatorial problems. Experimental results on three hard combinatorial optimization problems show that the approach is very effective and it enables considerable enhancement of the performance of saving-based algorithms. 相似文献
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虚拟自然景物技术发展到今天,构造虚拟植物的模型已经很多,但多数都侧重于图形学方面,主要研究对象在某一时刻的形态。受达尔文生物进化论思想启发,借鉴生物界自然选择和进化机制,从植物种群着手,以进化过程为研究对象,为实现计算机对植物进化过程模拟,提出了一种基于遗传算法和L-系统的植物进化模型。该模型无论对于计算机虚拟现实还是植物学研究都具有较高的实用价值。 相似文献
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差分进化算法是进化算法中一种性能较为优良的全局数值优化算法,已在人工智能、信号处理等方面取得广泛应用,但当前研究往往仅考虑进化过程中某一代种群的分布信息,而忽略进化过程中多代种群累积的分布信息,造成信息利用不充分。借助自适应协方差矩阵进化策略的思想,充分利用进化过程中累积的种群分布信息,同时,由于自适应协方差矩阵存在收敛早熟、易陷入局部最优的缺点,先后对变异和交叉操作进行相应改进,以平衡算法的全局搜索能力和局部搜索能力。首先,根据种群中个体适应度值进行排序,由余弦函数改进的概率模型计算个体参与变异操作的概率,基向量和差分向量中末端向量根据概率值降序选择,差分向量中起始向量升序选择,从而提高种群的搜索范围;然后,对协方差矩阵进行特征分解,并在由特征向量构建的坐标系中执行交叉操作,该种方式生成的实验向量更接近全局最优解。针对上述改进操作,采用IEEE CEC2014作为评估函数,实验结果表明,相比现有的差分进化改进算法,本改进算法的实验性能提升更为明显。 相似文献
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Over the last two decades, many sophisticated evolutionary algorithms have been introduced for solving constrained optimization problems. Due to the variability of characteristics in different COPs, no single algorithm performs consistently over a range of problems. In this paper, for a better coverage of the problem characteristics, we introduce an algorithm framework that uses multiple search operators in each generation. The appropriate mix of the search operators, for any given problem, is determined adaptively. The framework is tested by implementing two different algorithms. The performance of the algorithms is judged by solving 60 test instances taken from two constrained optimization benchmark sets from specialized literature. The first algorithm, which is a multi-operator based genetic algorithm (GA), shows a significant improvement over different versions of GA (each with a single one of these operators). The second algorithm, using differential evolution (DE), also confirms the benefit of the multi-operator algorithm by providing better and consistent solutions. The overall results demonstrated that both GA and DE based algorithms show competitive, if not better, performance as compared to the state of the art algorithms. 相似文献
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基于免疫遗传算法的软件测试数据自动生成 总被引:7,自引:0,他引:7
提出了一种应用于软件测试中的基于免疫遗传算法(IGA)的软件测试数据自动生成的算法。该算法在传统的遗传算法中引入免疫算子,免疫算子其中包括获取疫苗、注射疫苗和免疫选择。实验结果表明,该算法的效果比传统的遗传算法效果好。 相似文献
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隐私泄露问题已经成为阻碍基于位置的服务(location-based services,LBS)进一步发展的原因。针对当LBS用户发送查询时,用户的个人隐私可能会泄露给攻击者的问题,提出了基于遗传算法的空间网格划分的隐私保护算法(GAGP)。算法包括两个方法,即地图分割算法和假名生成法。地图分割算法利用遗传算法给每个网格赋权值,再通过使用邻接网格扩展的方法,保证每个划分区域的查询频率基本相等。假名生成法是用户在每次发送查询时使用假名来应对长期统计的攻击方式。通过实验证明所提算法与其他三种算法相比结果较好,所以提出的方案能够有效地保护用户的隐私。 相似文献
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《Information Processing Letters》2014,114(6):304-316
Path testing is the strongest coverage criterion in white box testing. Finding target paths is a key challenge in path testing. Genetic algorithms have been successfully used in many software testing activities such as generating test data, selecting test cases and test cases prioritization. In this paper, we introduce a new genetic algorithm for generating test paths. In this algorithm the length of the chromosome varies from iteration to another according to the change in the length of the path. Based on the proposed algorithm, we present a new technique for automatically generating a set of basis test paths which can be used as testing paths in any path testing method. The proposed technique uses a method to verify the independency of the generated paths to be included in the basis set of paths. In addition, this technique employs a method for checking the feasibility of the generated paths. We introduce new definitions for the key concepts of genetic algorithm such as chromosome representation, crossover, mutation, and fitness function to be compatible with path generation. In addition, we present a case study to show the efficiency of our technique. We conducted a set of experiments to evaluate the effectiveness of the proposed path generation technique. The results showed that the proposed technique causes substantial reduction in path generation effort, and that the proposed GA algorithm is effective in test path generation. 相似文献
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Since learning English is very popular in non-English speaking countries, developing modern assisted-learning tools that support effective English learning is a critical issue in the English-language education field. Learning English involves memorization and practice of a large number of vocabulary words and numerous grammatical structures. Vocabulary learning is a principal issue for English learning because vocabulary comprises the basic building blocks of English sentences. Therefore, many studies have attempted to improve the efficiency and performance when learning English vocabulary. With the accelerated growth in wireless and mobile technologies, mobile learning using mobile devices such as PDAs, tablet PCs, and cell phones has gradually become considered effective because it inherits all the advantages of e-learning and overcomes limitations of learning time and space that limit web-based learning systems. Therefore, this study presents a personalized mobile English vocabulary learning system based on Item Response Theory and learning memory cycle, which recommends appropriate English vocabulary for learning according to individual learner vocabulary ability and memory cycle. The proposed system has been successfully implemented on personal digital assistant (PDA) for personalized English vocabulary learning. The experimental results indicated that the proposed system could obviously promote the learning performances and interests of learners due to effective and flexible learning mode for English vocabulary learning. 相似文献