基于模糊阈值补偿的混合蛙跳算法

针对混合蛙跳算法(SFLA)求解复杂问题时收敛速度慢、优化精度低的缺点,提出一种基于模糊阈值补偿的混合蛙跳算法(FTCSFLA)。在SFLA的基础上,采用模糊分组方法对青蛙分组并改进局部搜索的扰动策略。在族群中定义模糊隶属度、隶属度阈值和补偿系数,利用邻域青蛙之间的分布程度衡量某一青蛙的模糊隶属度。在一次局部搜索中,对族群最差个体按模糊隶属度和隶属度阈值关系给出2种更新方法,设置相应的补偿系数。实验结果表明,隶属度阈值为0.9的FTCSFLA其收敛精度、速度均优于SFLA和隶属度阈值为0.5的FTCSFLA,当隶属度阈值取值在(0.5,0.9]之间时,FTCSFLA的性能达到最优。     

正态变异优胜劣汰的混合蛙跳算法

针对基本混合蛙跳算法收敛速度慢、求解精度不高且易陷入局部最优的缺陷,提出了一种新的正态变异优胜劣汰的混合蛙跳算法。该算法在局部搜索策略中,对子群内最差个体的更新融入了服从正态分布的变异扰动,可有效避免青蛙个体向局部最优聚集,扩大搜索空间,增加种群的多样性;同时对子群内少量的较差青蛙进行变异选择,摒弃不利的变异,继承有用的变异,优胜劣汰,整体提高种群的质量,减少算法寻优过程的盲目性,提高算法的寻优速度。对每个子群内的最优个体引入精英变异机制以获得更优秀的个体,进一步提升算法的全局寻优能力,避免陷入局部最优,引领种群向更好的方向进化。实验独立运行30次,所提算法在Sphere、Rastrigrin、Griewank、Ackley和Quadric函数中均能收敛到最优解0,优于其他对比算法。实验结果表明,所提算法可有效避免算法陷入早熟收敛,提高了算法的收敛速度和精度。     

嵌入共轭梯度法的混合蛙跳算法

针对基本蛙跳算法在处理复杂函数优化问题时求解精度低且易陷入局部最优的缺点,提出了一种嵌入共轭梯度法的混合蛙跳算法。该算法在基本蛙跳算法划分模因组的基础上引入共轭梯度法,由于基本蛙跳算法模因组的划分规则,使得排在最后的青蛙子群个体位置较差,严重影响着整个群体的寻优速度,因而选取排列在后面的一部分模因组使用共轭梯度法进行求解,这使得算法在进化中后期易跳出局部最优,提高了算法的收敛精度。所得混合蛙跳算法有效结合了基本蛙跳算法较强的全局搜索能力和共轭梯度法快速精确的局部搜索能力。数值实验结果表明,所提出的改进蛙跳算法较基本蛙跳算法具有更高的收敛精度,避免了陷入局部最优的缺点,且优化结果更加稳定。     

基于自适应权重调整与差分进化策略的并行式混合蛙跳算法

针对标准混合蛙跳算法（SFLA）在复杂优化问题中出现的收敛速度慢、求解精度不高和运行效率低等问题,提出了一种基于自适应权重调整与差分进化（DE）策略的并行式混合蛙跳算法（P-DE-ASFLA）。在局部搜索过程中,采用邻近学习策略更新子群中的最优个体以加快算法的收敛;采用动态蛙跳规则更新子群中的最差个体以避免算法早熟收敛;在全局搜索过程中,采用DE策略对混合后的种群进行基因更新,增强算法的全局寻优能力。同时基于主从式并行架构,采用多进程技术使子群的局部搜索过程并行化,大幅提高了算法的运行效率。实验结果表明,所提算法在6个标准测试函数中的求解质量和运行效率要远优于标准SFLA和DE算法。     

协同进化混合蛙跳算法

针对基本混合蛙跳算法收敛速度慢、求解精度低且易陷入局部最优的问题,提出了一种新的协同进化混合蛙跳算法。该算法在局部搜索策略中,对子群内最差个体的更新引入平均值的同时充分利用最优个体的优秀基因,可有效扩大搜索空间,增加种群的多样性;同时对子群内少量的较差青蛙采取交互学习策略向邻近子群的最优个体交流学习,增加子群间交互的频繁性,提高信息共享程度,有利于进化。在全局迭代过程中采取精英群自学习进化机制,以对精英空间进行精细搜索,获得更优解,进一步提升算法的全局寻优能力,正确导向算法的进化。实验结果表明,所提算法在七个测试函数中均能收敛到最优解0,成功率为100%,优于其他对比算法。所提算法可有效避免陷入早熟收敛,极大地提高了算法的收敛速度和优化精度。     

基于新搜索策略的混合蛙跳算法

混合蛙跳算法(SFLA)具有算法简单、控制参数少、易于实现等优点,但在高维优化问题中算法易早熟收敛且求解精度低。为此,提出一种基于新搜索策略的混合蛙跳算法(NSSFLA)。该算法定义了新的粒子分类标准,将所有青蛙按此标准进行分类,每类青蛙按照相应的位置更新公式进行更新;在迭代过程中,每个青蛙个体根据自身状态动态地调整惯性权重,平衡了算法全局搜索和局部搜索的能力;在全局迭代中借鉴柯西变异优化策略思想,并以停滞代数判断是否对最优个体进行优化,避免了族群陷入局部最优。实验仿真表明,NSSFLA的寻优能力强,迭代次数少,解的精度高,更适合高维复杂函数的优化。     

带有选择和自适应变异机制的混合蛙跳算法

混合蛙跳算法易陷入局部最优,且收敛速度较慢。为此,提出一种带有选择和自适应变异机制的蛙跳算法。引入线性递减的动态惯性权重修正最差青蛙,按照一定的概率选择适应度值较优的青蛙代替较差青蛙,并对每只青蛙个体以不同概率进行自适应变异。仿真结果表明,该算法可以平衡全局搜索和局部搜索,寻优能力强、迭代次数少,解的精度较高,更适合高维复杂函数的优化。     

一种改进的混合蛙跳和K均值结合的聚类算法

传统K均值聚类(KMC)算法过分依赖初始值的设置,容易陷入局部最优;混合蛙跳算法(SFLA)存在收敛速度和搜索速度较慢、局部和全局信息交流不全面等缺点。针对以上缺点,首先提出一种改进的混合蛙跳算法(MSFLA)。该算法根据粒子群优化和差分进化思想,在青蛙个体变异时,引入上一次移动距离的权重惯性系数和缩放因子,从种群中的最优位置和历史最优位置之间的随机点出发,以子群内的青蛙的平均值和最差位置差值为步长进行青蛙个体的更新操作。再将MSFLA与KMC算法结合提出MSFLA-KMC算法,有效地克服了KMC算法过分依赖初始值设置问题,同时降低了KMC算法陷入局部最优的可能性。实验结果表明,MSFLA具有较强的寻优能力,MSFLA-KMC算法则具有更好的聚类性能。     

基于差分扰动的混合蛙跳算法

针对基本混合蛙跳算法在处理复杂函数优化问题时容易陷入局部最优、求解精度低的缺点,借鉴差分进化中的变异思想,提出了一种改进的混合蛙跳算法,利用子群中其他个体的有利信息,对其更新策略进行局部扰动。实验结果表明,改进的混合蛙跳算法对复杂函数优化问题具有较强的求解能力。算法寻优效率高、全局性能好、优化结果稳定,性能明显优于所比较的算法。     

一种新颖的差分混合蛙跳算法

在使用智能优化算法处理函数优化问题时,保持种群的多样性及加快种群的收敛速度可以提升一个算法的性能.针对混合蛙跳算法在寻优过程中易陷入局部最优和早熟收敛的缺点,本文提出了一种新颖的差分混合蛙跳算法.该算法借鉴差分进化中的变异交叉思想,在前期利用子群中其他个体的有用信息来更新最差个体,增加局部扰动性,以提高种群的多样性;在后期为加快收敛速度使用最好个体的信息进行变异交叉操作.同时本文使用归档集进一步保留种群的多样性.仿真测试结果表明:该算法在求解优化问题时较基本蛙跳算法和平均值蛙跳算法具有更好的寻优性能.     

煤矿井下安全监控分站的设计及其仿真实现

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.     

View-based model-driven architecture for enhancing maintainability of data access services

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.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

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.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

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.     

Software-Konfigurationsmanagement in großen Softwareprojekten

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.     

Information for Authors

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     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

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     

Information for Authors

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     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

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