基于混合并行遗传算法的多目标约束优化技术研究

多目标约束优化问题属于NP问题。并行遗传算法是解决该类问题的常用算法,它具有较强的全局搜索能力和并行性,但局部搜索能力差,禁忌搜索算法则比较适合于局部搜索。提出了一种基于混合并行遗传算法的多目标约束优化方法,该方法综合了并行遗传算法和禁忌搜索算法的优势,改进了并行遗传算法的性能,能有效避免局部最优解。     

求解置换流水车间调度问题的改进遗传算法

针对置换流水车间调度问题的基本特征和传统遗传算法易早熟的缺陷,设计了改进遗传算法来求解此问题。采用NEH和Palmer启发式算法进行种群初始化,以提高初始解的质量;根据Metropolis准则对染色体进行选择操作,避免陷入局部最优;在变异过程中引入禁忌算法,避免迂回搜索;在算法迭代过程中引入了保优机制,避免丢失优秀染色体的基因信息;采用自适应终止准则,以保证解的质量。基于典型Benchmark算例的仿真实验结果表明,算法在求解质量和收敛速度方面明显优于NEH算法和种群经过初始优化的传统遗传算法。     

多目标资源优化分配问题的Memetic 算法

针对传统算法求解多目标资源优化分配问题收敛慢、Pareto解不能有效分布在Pareto 前沿面的问题, 提出一种新的Memetic 算法. 在遗传算法的交叉算子中引入模拟退火算法, 加强了遗传算法的局部搜索能力, 加快了收敛速度. 为了使Pareto 最优解均匀分布在Pareto 前沿面, 在染色体编码中引入禁忌表, 增加了种群的多样性, 避免了传统遗传算法后期Pareto 解集过于集中的缺点. 通过与已有的遗传算法、蚁群算法、粒子群算法进行比较, 仿真实验表明了所提出算法的有效性, 并分析了禁忌表长度和模拟退火参数对算法收敛性的影响.

     

一种求解车间作业调度的自适应混合遗传算法

针对遗传算法和禁忌搜索算法在求解车间作业调度问题存在的全局收敛性差、种群早熟化、收敛速度慢等缺陷,提出了一种自适应遗传禁忌搜索算法。算法通过自适应调整遗传算子中的变异概率,改善了遗传算法的收敛速度;通过增加禁忌表来选择杂交产生的个体,避免迂回搜索,以禁忌搜索算法作为变异算子,增加种群的多样性,避免算法陷入局部最优。通过仿真实例,验证了算法的收敛性和抗局部收敛性。     

电力系统PMU最优配置问题的混合优化算法

针对电力系统潮流计算方程直接可解的PMU最优配置问题,提出了一种引入小生境技术的遗传禁忌搜索混合算法。混合优化算法以小生境遗传算法为主体,避免传统遗传算法“早熟”和解的多样性不足的问题;结合禁忌搜索思想,使用TSR算子进行交叉操作,解决传统遗传算法局部搜索能力较差和收敛速度有待提高的问题。用该算法与其他两种传统算法进行了对比验证,结果表明该混合算法不仅能寻得全局最优解,而且提供了解的多样性,提高了优化效率,具有广阔的应用前景。     

遗传和禁忌搜索算法在多车物流配送问题中的应用

多车物流配送策略属于物流的统筹配给范畴,应用十分广泛.考虑到遗传算法存在早熟收敛和盲目搜索问题,把禁忌搜索算法独有的记忆思想引入到遗传算法的搜索过程中,将禁忌搜索算法作为遗传算法的变异算子,提出了基于遗传和禁忌搜索的组合算法,并通过与纯遗传算法的比较证实该算法的有效性.     

有时间窗约束车辆路径问题的改进遗传算法

将遗传算法与禁忌搜索结合起来,设计了一种改进的遗传算法求解有时间窗约束车辆路径问题。采用启发式插入算法产生较优良的遗传操作初始种群,通过改进的逆转变异算子更多继承父代的优良性能,以提高遗传算法的计算效率。引入海明距评估遗传进化中种群的多样性。当种群多样性低到一定程度时转入禁忌搜索,以避免遗传算法早熟的缺陷,最终实现全局优化。通过算例验证了该算法的优越性。     

基于遗传和禁忌搜索混合的软硬件划分算法

针对嵌入式系统软硬件划分问题,在比较了遗传算法（GA）和禁忌搜索（TS）各自优缺点的基础上,提出采用遗传/禁忌混合算法（GATS）的策略,用遗传算法提供并行搜索的主框架,用禁忌搜索作为遗传算法的变异算子,遗传算法中变异过程解空间的搜索由禁忌搜索实现。实验结果表明,GATS具有多出发点和记忆功能强、爬山能力强的优势,能够克服GA爬山能力差、TS单点出发的弱点。最后与单纯的遗传算法和禁忌搜索算法进行对比实验,证明GATS更有优势,得到的划分结果也更优秀。     

采用组合优化策略的电子侦察卫星规划方法

对电子侦察卫星任务规划问题进行了分析,建立了问题的多目标规划模型;设计了一种基于带后优化过程MOEO(Multi-objective Extremal Optimization)的多目标规划算法对模型进行求解,该算法包含MOEO主算法过程和基于禁忌搜索(TS)的后优化过程两部分:MOEO主算法中采用插入变异、模式变异及删除变异等算子对解空间进行搜索,基于Pareto最优概念的解排序确保了解在多个目标上的有效优化,精英策略避免了丢失进化过程中产生的非劣解;TS后优化过程中提出了多种邻域结构,使用各种邻域算子或算子的组合,对主算法Pareto最优解进一步优化,以得到更好的解。最后给出了仿真实例证明本文模型及算法对解决电子侦察卫星任务规划问题的有效性。     

考虑时间与能耗约束的柔性作业车间调度优化

随着能源价格日益上涨以及国家节能减排措施的不断推进,制造业正朝着绿色生产方向转型。针对受调整时间和能耗约束的柔性作业车间调度问题,建立以最大完工时间、总调整时间和总能耗为目标的数学模型。设计改进的NSGA-Ⅱ与禁忌搜索结合的多目标混合算法（MOGATS）进行求解。算法设计三种初始化规则保证初始解的质量和多样性。为提高算法搜索效果,将Pareto等级引入交叉算子中,并在变异算子中加入模拟退火算法提升算法的局部搜索能力。最后,在Pareto前沿中找到各个目标的最优个体作为初始解,进行禁忌搜索以提高解的质量。通过与其他算法的实验结果进行对比,验证MOGATS算法能够有效求解考虑机器调整的柔性作业车间多目标问题。     

European Community policy and the market

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.     

一种自适应子融合集成多分类器方法

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。     

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.     

Explanation and prediction: an architecture for default and abductive reasoning

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.     

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.     

Three Process Perspectives: Organizations, Teams, and People

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.     

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.     

基于复小波噪声方差显著修正的SAR图像去噪

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。