基于非支配解排序的快速多目标微分进化算法

为解决基于帕累托(Pareto)支配解排序的多目标进化算法高时间复杂度问题,依据非支配解排序潜在特性,介绍了一种快速的非支配解排序方法,每次只处理当前种群中最高等级个体,且在分配等级的同时,能选择个体进入下一代,下一代被选足时即结束程序,减少了排序处理个体的数量,大幅度降低时间复杂度;另外,给出一种均匀的拥挤距离计算方法;最后,将快速非支配解排序和均匀拥挤距离计算与微分进化算法结合,提出基于非支配解排序的快速多目标微分进化算法(FMODE)。采用标准多目标优化问题ZDTl～ZDT4和ZDT6进行仿真实验：当种群个体较多(大于500)时,FMODE所用时间远小于NSGAⅡ;FMODE的总体性能上均优于经典的NSGAⅡ、SPEAⅡ和DEMO;在FMODE框架内,采用均匀拥挤距离在性能上也明显优于经典拥挤计算方法;并通过实验确定了FMODE算法的参数。实验结果表明FMODE能够减少计算等级时的处理时间,并在收敛性和多样性指标上明显优于对比算法。     

具有多形态种群协同进化的多目标优化算法

为提高进化多目标优化算法在维持最优解多样性方面的性能,获得分布更均匀的Pareto非支配解集,文中提出一种具有多形态种群协同进化的多目标优化算法.该算法构建一种多形态种群协同进化架构,通过引入最小向量夹角的相似性度量方法,给出次优非支配个体选择策略,从而提高种群的多样性.算法还提出一种基于排序链表的拥挤个体删除策略,进一步提高解集分布的均匀性和宽广性.与经典算法对比结果表明,文中算法在解的分布性和多样性方面均有较好表现,尤其在解集分布均匀性方面优势较明显.     

基于差分进化粒子群算法的多目标无功优化

针对电力系统有功网损最小、电压水平最好和电压稳定裕度最大的多目标无功优化问题,提出一种基于差分进化的改进多目标粒子群优化算法。该算法通过对Pareto最优解集的差分进化来增加Pareto最优解的多样性,通过拥挤距离来控制精英集中非支配解的分布,以提高对种群空间的均匀采集;采用擂台赛法则构造多目标Pareto最优解集,较大程度的提高了算法的运行效率;自适应惯性权重和加速度因子的动态变化可增强算法的全局搜索能力。将该算法在IEEE14、IEEE30节点标准测试系统上进行了无功优化仿真,结果表明,基于差分进化的改进多目标粒子群优化算法能够在保持Pareto最优解的多样性的同时具有较好的收敛性能,为多目标无功优化提供了一种新的方法。     

一种基于聚集距离的多目标进化算法

在多目标进化算法的研究中,解群体的多样性和运行效率是最重要的两个指标。在进化算法中一般采用构造非支配集的方法来保持算法的运行效率和解集的分布性;采用聚类技术来计算和维持解群体的分布性和多样性。文章提出了用庄家法构造非支配集和基于个体距离的聚类方法的多目标进化算法。经试验证明,该算法能够趋近到Pareto最优解,并且能保证较好的分布度。     

一种改进的多目标混合差分进化算法

将差分进化算法（DE）用于多目标优化问题,提出了一种精英保留和进化进程中非支配解集迁移操作的差分进化算法,以保证所求得多目标优化问题Pareto最优解的多样性。采用双群体约束处理技术,构建进化群体的Pareto非支配解外部存档集,并进行基于非支配解集的迁移操作,以增加非支配解的数目和质量。用多个经典测试函数测试的结果表明,与标准DE相比,该方法收敛到问题的Pareto前沿效果良好,能有效保持Pareto最优解多样性与收敛之间的平衡。     

求解多目标作业车间调度问题的混合变异杂草优化算法

针对多目标作业车间调度问题,提出一种混合变异杂草优化算法。该算法采用基于各子目标熵值权重的欧氏贴近度作为适应度值计算方法,引导种群向Pareto前端进化。在进化过程中,运用快速非支配排序策略构建Pareto档案,并利用进化种群中最优个体实时更新Pareto最优解集,提升算法的优化性能;同时通过引入变异算子增加种群多样性,避免算法陷入局部最优。最后,基于Benchmark算例的仿真实验,验证了该算法求解多目标作业车间调度问题的有效性。     

随机扰动不同种群变异策略的多目标进化算法

为了提高多目标优化问题非支配解集的收敛性和多样性,解决算法后期易陷入局部最优的问题,根据不同差分进化策略特点,添加随机扰动,基于改进切比雪夫机制提出了一种自适应差分进化策略的分解多目标进化算法（MOEA/D-ADE-levy）。首先使用混合水平正交实验产生均匀权重向量并应用于改进切比雪夫机制分解子问题得到均匀分布的初始种群;其次将种群分为优秀个体、中间个体和较差个体,对不同个体采用不同的变异策略,对变异因子F和交叉概率CR采用自适应机制,提高非支配解集的收敛性和多样性;最后对陷入局部最优的解集增加levy随机扰动,增大其全局搜索的能力,跳出局部最优。采用DTLZ测试函数验证算法有效性,将所提算法与NSGA2、NSGA3、MOEA\D、MOEA\D-DE等常用算法进行比较,使用GD和IGD评价指标对算法进行多样性和收敛性分析,实验结果表明,该算法在收敛性和多样性方面得到了改进与提高,能得到更优的Pareto解集。     

多目标优化差分进化算法

个体的适应度赋值和群体的多样性维护是进化算法的两个关键问题。首先,一方面,定义了Paretoε-支配关系的相关概念,通过Paretoε-支配关系确定个体的强度Pareto值,根据个体的强度Pareto值对群体进行Pareto分级排序,实现优胜劣汰;另一方面,使用拥挤距离估算个体的拥挤密度,淘汰位于拥挤区的一些个体,维持群体的多样性。然后,根据差分进化算法的特点,使用适当的进化策略和控制参数,给出了一种用于求解多目标优化问题的差分进化算法DEAMO。最后,数值实验表明,DEAMO在求解标准的多目标优化问题时性能表现优良。     

求解约束高维多目标问题的分解约束支配NSGA-II优化算法

针对多目标进化算法处理约束高维多目标优化问题时出现解的分布性和收敛性差、易陷入局部最优解问题,采用Pareto支配、分解与约束支配融合的方法,提出一种基于分解约束支配NSGA-II优化算法(DBCDP-NSGA-II).该算法在保留NSGA-II中快速非支配排序的基础上,首先采用Pareto支配对种群进行支配排序;然后根据解的性质采用分解约束支配(DBCDP)惩罚等价解,保留稀疏区域的可行解和非可行解,提高种群的分布性、多样性和收敛性;最后采用个体到权重向量的垂直距离和拥挤度距离对临界值进行再排序,直到选出N个最优个体进入下一次迭代.以约束DTLZ问题中C-DTLZ1、C-DTLZ2、DTLZ8、DTLZ9测试函数为例,将所提出的算法与C-NSGA-II、C-NSGA-III、C-MOEA/D和C-MOEA/DD进行对比分析.仿真结果表明,DBCDP-NSGA-II所得最优解分布更加均匀,具有更好的全局收敛性.     

求解多目标流水车间调度Pareto最优解的遗传强化算法

针对多目标流水车间调度Pareto最优问题, 本文建立了以最大完工时间和最大拖延时间为优化目标的多目标流水车间调度问题模型, 并设计了一种基于Q-learning的遗传强化学习算法求解该问题的Pareto最优解. 该算法引入状态变量和动作变量, 通过Q-learning算法获得初始种群, 以提高初始解质量. 在算法进化过程中, 利用Q表指导变异操作, 扩大局部搜索范围. 采用Pareto快速非支配排序以及拥挤度计算提高解的质量以及多样性, 逐步获得Pareto最优解. 通过与遗传算法、NSGA-II算法和Q-learning算法进行对比实验, 验证了改进后的遗传强化算法在求解多目标流水车间调度问题Pareto最优解的有效性.     

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