首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
刘翱  邓旭东  李维刚 《计算机应用》2016,36(11):3055-3061
针对标准萤火虫算法(FA),首先,从数学理论上分析并揭示了其存在的种群过早收敛、容易陷入局部最优等不足,然后提出一种基于模拟退火的混合萤火虫Memetic算法。该算法利用标准萤火虫算法对上一代种群进行全局搜索以保持种群的多样性和算法的全局探索能力;使用模拟退火算子对当前种群中的部分个体进行局部搜索,以一定概率接受适应度较差的个体以避免算法陷入局部最优,该算法同步进行萤火虫吸引过程和模拟退火过程以降低算法复杂度。最后,对该算法在10个标准测试函数上进行对比仿真实验。实验结果表明,该算法在6个测试函数中均能找到最优解,最优值、平均值、方差等指标比对比算法高出一定数量级,在4个复合函数中效果均优于萤火虫算法。  相似文献   

2.
针对传统萤火虫算法(FA)中存在的过早收敛和易陷入局部最优解等问题,提出了一种基于模拟退火机制的多种群萤火虫算法(MFA_SA):将萤火虫种群平均分为参数不同的多个子种群。为了防止算法陷入局部最优解,利用模拟退火机制大概率接受较好的解,小概率接受较差的解。同时,在种群寻优的过程中引入可变的距离权重,通过萤火虫算法的迭代次数动态调整萤火虫的"视野"范围。利用5个标准测试函数对该算法进行了对比仿真测试,结果表明,该算法在4个测试函数中均能寻找到全局最优解,并且在最优值、平均值、方差等指标上均比对比算法高出多个数量级,验证了新算法的有效性。  相似文献   

3.
一种基于多样化成长策略的遗传算法   总被引:1,自引:0,他引:1  
遗传算法中,部分局部最优个体常常会抑制种群中其他个体的成长,使进化停滞,结果陷入局部最优.对此,提出一种基于多样化成长策略的遗传算法,通过采用迁移杂交、多态变异和群体突变等方法,对种群中不同适应度的个体给予不同的进化成长策略,以保持个体间的多样性,从而增强算法的寻优能力.对改进算法的算法复杂度进行了分析,并通过算例表明,多样化成长策略的各个部分均对改善寻优结果发挥了作用.  相似文献   

4.
针对多目标萤火虫算法在解决复杂多目标问题时存在收敛性差和分布性不足的问题,提出了基于动态反向学习和莱维飞行的双搜索模式萤火虫算法(MOFA-LR)。该算法通过比较任意一只萤火虫与种群中其余萤火虫的适应度值,判断它们之间的支配关系,根据不同的支配关系选择不同的搜索模式。当萤火虫被支配时,应注重向帕累托前沿上的优质解靠近,因此通过动态反向学习策略求出当前个体的反向解,使用反向解结合全局最优解共同引导萤火虫移动的搜索模式,能够发掘潜在的较好解,使萤火虫最大可能地向有利方向移动,改善了算法的收敛性;当萤火虫不被支配时,应注重获得均匀分布的帕累托前沿,因此使用全局最优解引导萤火虫飞行并结合莱维扰动的搜索模式,既能有效利用非支配解的优良信息,又能避免算法陷入停滞,在改善算法收敛性的同时维护了分布性。最后,为避免算法在迭代后期出现萤火虫严重聚集的现象,添加变异算子帮助种群跳出局部最优,引导种群进行局部开采。将MOFA-LR与12种新近多目标优化算法进行比较,实验结果表明,MOFA-LR具有良好的收敛性和分布性,证明了所提策略的有效性。  相似文献   

5.
萤火虫算法是一种生物群智能的随机优化算法,该算法通过模拟萤火虫在觅食、择偶中产生荧光而相互吸引、移动、合作等行为来解决最优化问题。虽然该算法具有设置参数少、原理简单、更新公式清晰等优点,但是存在着种群过早收敛到局部最优解或者种群收敛速度慢等问题。为此本文提出蛙跳萤火虫算法。该算法利用蛙跳的分群思想来优化萤火虫算法。利用蛙跳算法对种群进行分群和局部深度优化,不断地迭代以寻得最优解。在对蛙跳萤火虫算法研究的基础上把它应用于无线电频谱分配中,获得比较满意的频谱分配方式。  相似文献   

6.
针对差分进化算法在处理函数优化时存在的过早收敛和易陷入局部最优的问题,提出了一种基于精英种群策略的协同差分进化算法。在优化过程中,首先对种群进行适应度值评估和排序,提取前N个优秀个体组成精英种群,其余个体随机分为3个等大的子种群,每个子种群采取不同的进化策略,以此来保证种群的多样性;然后每隔一定代数,根据新的适应度值更新精英种群和其余3个子种群,这样可以有效地避免算法陷入局部最优;最后,将所提出的算法与4个先进的差分进化算法在CEC2014的30个标准测试函数上进行对比实验。实验结果表明,所提出的算法能够有效提高收敛速度,具有较高的收敛精度和较好的优化性能。  相似文献   

7.
并行遗传算法收敛性分析及优化运算   总被引:3,自引:1,他引:3  
经典遗传算法(Canonical Genetic Algorihms)利用单一种群对种群个体进行交叉、变异和选择操作,在进行过程中的超级个体易产生过早收敛现象,粗粒度并行遗传算法利用多个子群进行进化计算,各子群体分别独立进行遗传操作,相互交换最优个体后继续进化。文证明了该算法的搜索过程是一个有限时齐遍历马尔柯夫链,给出粗粒度并行遗传算法全局最优收敛性证明。对于旅行商问题TSP(Traveling Salesman Problem)利用粗粒度并行遗传算法进行了求解,以解决经典遗传算法的收敛到局部最优值问题。仿真结果表明,算法的收敛性能优于经典遗传算法。  相似文献   

8.
提出一种改进的蜜蜂进化型遗传算法.在该算法中,种群的最优个体作为蜂王与被选的每个个体(雄蜂)以一定概率进行交叉操作,从而增强了对种群最优个体所包含信息的开采能力;同时,为了避免过早收敛,算法在种群次优解周围进行局部搜索,引入新的随机个体,增加算法的多样性.实验结果表明,该算法能有效地提高遗传算法性能的求解精度和收敛速度.  相似文献   

9.

遗传算法中,部分局部最优个体常常会抑制种群中其他个体的成长,使进化停滞,结果陷入局部最优.对此,提出一种基于多样化成长策略的遗传算法,通过采用迁移杂交、多态变异和群体突变等方法,对种群中不同适应度的个体给予不同的进化成长策略,以保持个体间的多样性,从而增强算法的寻优能力.对改进算法的算法复杂度进行了分析,并通过算例表明,多样化成长策略的各个部分均对改善寻优结果发挥了作用.

  相似文献   

10.
李影  邢伟 《控制工程》2007,14(6):583-585
由于在进化算法中,一般的选择算子使适应度小的个体很早被淘汰,使它们的一些优良特征无法在种群中得到传播,但却增大了种群中优良个体繁衍的机会,因此可能会导致过早收敛或仅得到局部最优。对该算法加以改进,根据个体是否可行,将种群分为可行个体及非可行个体两部分,这样非可行个体也有机会参与到进化中。仿真结果表明,该方法对求解约束优化问题是很有效的。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.  相似文献   

18.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

19.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

20.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  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-23

京公网安备 11010802026262号