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为了解决混合无线传感器网络的节点覆盖率低的问题,提出了改进粒子群的混合无线传感器网络节点覆盖迭代优化算法.在该算法中,首先将混合无线传感器网络节点覆盖模型转化为在网络系统中动态的求覆盖率最大值的节点部署位置寻优问题;然后提出利用改进粒子群算法对节点覆盖优化方案进行粒子及其权值映射,并依据粒子粒距聚类度和粒子信息熵对粒子权值进行调整,再依据粒子适应度值对粒子局部最优值和全局最优值进行更新;最后迭代地对粒子的位置和速度进行计算,输出具有最优覆盖率的节点部署方案.仿真结果证明,该算法能够有效的提升网络覆盖率,且算法的收敛速度快. 相似文献
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针对标准BP算法收敛速度慢及易陷入局部极值等问题,提出一种基于粒子群优化与BP混合算法的神经网络学习方法。该方法在网络的训练过程中,同时利用粒子群算法与BP算法进行最优网络权值的搜索,从而既充分利用了粒子群算法的全局搜索性又较好地保持了BP算法本身的反向传播特点。将该混合学习算法应用于复杂函数的拟合仿真,并与标准BP算法以及传统的粒子群优化BP神经网络学习算法进行比较。实验结果表明所提的混合学习算法具有较高的收敛精度,且收敛速度更快。 相似文献
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一种改进的自适应惯性权重粒子群优化算法 总被引:1,自引:0,他引:1
研究粒子群算法优化问题,针对基本粒子群算法早熟收敛,易收敛于局部极值的缺点,提出了一种改进的粒子群算法,采用对全局最优微扰和调整惯性权重的方法,改善算法的优化速度和收敛精度.利用个体寻优能力来定义惯性权重,并且将其控制在0.9-0.4范围内,从而合理地调整全局探索能力和局部开发能力.在每次迭代时对当前全局最优粒子进行微扰,改变它的位置,避免它陷入局部最优.经过对一系列测试函数的计算和比较,证明改进方法无论收敛速度、搜索精度及稳定性均有显著改善. 相似文献
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研究粒子群优化算法.传统的粒子群算法采用实数编码,收敛速度慢.为了提高收敛速度,提出了一种混沌编码的粒子群优化算法.混沌编码作为一种全新的数学编码方式,更能准确地表达编码对象的多样性,将混沌编码应用到粒子群优化算法中,使算法在初期的搜索区域更大,更快找到全局最优解.把混沌编码的粒子群算法与BP算法相结合用来优化神经网络.利用混沌编码的粒子群算法快速找到全局最优位置的邻域,然后再用BP算法进行局部寻优,收敛到全局最优位置.仿真结果证明混沌编码的粒子群神经网络比实数编码的粒子群神经网络分类收敛速度更快,验证了算法的有效性. 相似文献
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针对高维优化问题,随机初始化的粒子群算法中不同维的收敛情况不同,常用惯性权重不能很好地平衡全局搜索和局部搜索,且算法也易陷入局部最优。本文提出一种基于惯性权重维正弦调整和t分布维变异的粒子群优化算法,兼顾各维的收敛情况,较好地保持了种群的多样性。通过4个典型函数的测试,结果表明改进算法提高了收敛速度和精度。 相似文献
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一种新的混合变异粒子群算法 总被引:1,自引:1,他引:1
针对基本PSO算法存在易陷入局部最优点的缺点,提出了一种新型的PSO算法——混合变异粒子群算法。在每次迭代中,符合变异条件的粒子,以多种变异函数方式进行变异,而这些变异函数被赋予了一定概率,概率的划分取决于特定的优化问题。对几种典型函数的测试结果表明:在变异函数概率分配设置合适的情况下,混合变异粒子群算法增强了全局搜索能力,提高了搜索成功率,克服了基本PSO算法易于收敛到局部最优点的缺点,也明显优于单变异粒子群算法。 相似文献
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张涛 《计算机测量与控制》2015,23(1):86-89
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
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Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China. 相似文献
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In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times. 相似文献
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《Information & Management》2016,53(6):787-802
Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice. 相似文献
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Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs. 相似文献
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Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel. 相似文献
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《浙江大学学报:C卷英文版》2014,(11)
正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and 相似文献
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Zhao-hui WU 《浙江大学学报:C卷英文版》2014,(10)
正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control 相似文献
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《浙江大学学报:C卷英文版》2014,(10)
正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate 相似文献