时变压缩因子粒子群算法

针对粒子群算法对全局和局部搜索平衡能力较弱的缺点,提出结合时变加速因子的粒子群算法。新算法基于压缩因子粒子群算法,利用双重压缩因子;第一个压缩因子用来调节全局和局部搜索模型;第二压缩因子利用时变的加速因子,进一步平衡全局和局部最优值对粒子种群升级的影响;通过对基本粒子群算法,压缩因子粒子群算法和混沌粒子群算法在8个标准Benchmark函数上进行三种测试,实验结果表明新算法精度较高,收敛速度较快。新算法通过时变的加速因子,较好平衡了粒子群算法的全局和局部搜索模型。     

基于高斯混沌变异和精英学习的自适应多目标粒子群算法

为平衡多目标粒子群的全局和局部搜索能力, 提出一种基于高斯混沌变异和精英学习的自适应多目标粒子群算法. 首先, 提出一种新的种群收敛状态检测方法, 自适应调整惯性权重和学习因子的值, 以达到探索和开发的最佳平衡. 然后, 当检测到种群收敛停滞时, 采用一种带有高斯函数和混沌特性的变异算子协助种群跳出局部最优, 以增强全局搜索能力. 最后, 外部档案中的精英解相互学习, 增强算法的局部搜索能力. 在多目标标准测试问题上的仿真结果表明了所提出算法的有效性.

     

基于混沌变异的自适应双粒子群优化

针对粒子群优化在解决高维优化问题时收敛性差、搜索效率不高的问题,在对粒子群优化算法收敛性分析的基础上,提出了混沌变异对极值进行扰动的方法,以增强算法摆脱局部最优解的能力.采用自适应惯性权重和局部邻域搜索保持较高的局部搜索性能,并结合双粒子群协同进化的方法,综合平衡优化算法的全局搜索和局部搜索能力.通过对4个典型测试函数进行的对比实验,表明了所提出的算法能大大提高粒子群优化的搜索效率和收敛精度.     

带扰动因子的自适应粒子群优化算法

针对标准粒子群优化算法搜索精度不高、易陷入局部最优的问题,提出了一种带扰动因子的自适应粒子群优化算法。该算法进行混沌初始化,采用自适应的惯性权重,并将扰动因子加入粒子个体极值、全局极值和位置更新公式中。通过与其它算法的数值实验对比,新算法能够有效避免局部最优,全局收敛性能显著提高,收敛速度更快。     

改进的粒子群优化算法的研究和分析

粒子群优化算法是一种新的随机全局优化进化算法。为了有效地控制其全局搜索和局部搜索,使之获得较好的平衡,论文在深入分析和研究标准粒子群优化算法的基础上,提出了一种基于进化代数阈值和粒子间最大聚集距离高斯变异的粒子群优化算法。该算法在运行过程中通过粒子聚集程度的量化判定,对当前的最优粒子施加高斯变异,从而增强粒子群优化算法跳出局部最优解的能力。测试函数仿真结果表明了该算法的可行性和有效性。     

一种带混沌变异的粒子群优化算法

为了克服粒子群算法在进化后期存在收敛速度慢、易陷入局部极小等问题,提出了一种混沌变异粒子群优化算法。该算法根据群体适应度变化率对种群中非优胜粒子进行变异操作,并对全局最优位置进行小范围混沌扰动,以增强算法跳出局部最优的能力。对几种复杂典型函数与标准粒子群算法进行了仿真测试,结果表明该算法明显改善了全局搜索能力和抗早熟收敛性能。     

嵌入列维变异的混合动态粒子群算法

针对标准粒子群优化算法易陷入局部最优、收敛精度不高的问题,提出一种嵌入列维变异的混合动态粒子群算法（DLPSO）。算法在进化过程中采用动态拓扑Dbest策略以降低粒子趋同性,每次迭代时根据解的好坏将粒子分为全局最优粒子、探索粒子及无目标粒子,并对探索粒子进行分簇,簇内粒子的更新受到全局最优粒子及簇内最优粒子的共同影响;为确保粒子多样性,平衡局部搜索与全局搜索,采用免疫机制与自适应列维变异相结合的方式对粒子进行变异。利用7个测试函数对算法进行性能评价,数值仿真结果表明该算法搜索精度高且稳定性好,具有良好的收敛性能。     

基于混沌局部搜索的粒子群算法及其应用

为提高混沌优化搜索结果的精度,在以粒子群算法进行全局搜索的基础上,根据全局搜索结果利用混沌优化进行局部搜索,实现在全局范围上搜索最优值。分析局部混沌搜索方法,设计基于混沌局部搜索的粒子群算法的流程,利用混沌优化进行粒子群局部搜索以跳出局部最优搜索区域,避免陷入局部极小值和实现在全局范围上搜索目标函数的最优值。以RMSE误差作为搜索结果精度评价指标,通过Rosenbrock函数算例对基于混沌局部搜索的粒子群算法精度进行分析,并将该算法应用于停车场最优选址实际问题的决策。研究结果表明,该算法搜索结果相较于混沌优化算法搜索结果具有更高的精度,其数值更逼近理论最优值,验证了其提高搜索结果精度的有效性和在解决实际问题上的可行性。     

惯性权重动态调整的混沌粒子群算法

鉴于标准粒子群算法(PSO)有易陷入局部最优位置和全局搜索能力差等缺点,给出了相似度的定义,并根据群体中每个粒子与全局最优粒子的相似度值的大小,动态非线性地更新每个粒子的惯性权重值。为了改善算法的全局搜索性能,将混沌算子引入粒子群算法中。新算法在4个测试函数上与标准粒子群算法进行了比较,结果表明新算法的性能更好。     

带双重变异算子的自适应粒子群优化算法

提出了一种双重变异自适应粒子群优化算法,该算法除了使用自适应算子来改变惯性权重外,还在搜索过程中使用非均匀变异算子对位移进行变异,扩大位移的搜索范围.当算法陷入局部收敛时,使用柯西变异算子对全局最优解进行变异,促使粒子逃离局部最优的陷阱,从而最大限度的提升算法全局搜索的性能.通过对4个标准函数的测试,新算法的全局搜索能力有了显著提高,并且能够有效避免早熟收敛的陷阱.     

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)

正~~     

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