软件体系结构动态演化的元胞自动机模型研究

目前软件体系结构动态演化的元胞自动机模型存在描述单一、元胞间关系不明确、没有详细阐述动态演化过程应用约束条件的缺点。针对这些不足进行相关的研究,重新定义了软件体系结构动态演化的扩展元胞自动机模型,基于扩展元胞自动机模型结合演化应用约束条件,分析了软件体系结构的动态演化过程,运用元胞间控制约束条件和行为相关约束条件来正确地指导SA动态演化。提出了动点稳态转移的概念,对演化程度和一致性进行定义分析,此方法比以往的元胞自动机模型更能准确指导SA动态演化,促进SA动态演化的进一步研究。通过案例验证了该方法的应用价值和可行性,可以更全面地应用于软件体系结构的动态演化。     

基于不动点转移的SA动态演化模型

构造性和演化性是软件的两个基本特性．而软件演化包括静态演化和动态演化两个方面．动态演化更为复杂，这种复杂性决定了．对动态演化的研究首先应从宏观层面人手．软件体系结构SA作为软件的蓝图和支撑骨架．为人们宏观把握软件的动态演化提供了一条有效的途径．该文描述了构件——连接件组成的SA动态语义网络模型．分析了SA动态语义网络模型中的浸润过程．给出基于不动点的浸润过程收敛的判定，提出了邻接矩阵过滤和原子过滤的概念，阐明了基于邻接矩阵原子过滤的SA动态语义网络浸润步的原子性．指出SA动态演化过程可用一系列邻接矩阵原子过滤在时刻上相继的逻辑衔接来描述．最后给出了两个层面上对SA动态演化波及效应的分析方法．为基于矩阵变换的SA动态演化的进一步研究和计算机自动量化描述奠定了基础．     

基于非功能需求的软件体系结构演化

对非功能需求NFRs进行了描述,根据功能需求、NFRs与SA的关系,定义了基于NFRs的SA演化,使用构件组合运算和结构工作链对软件体系结构的非功能特性进行了评估,根据评估结果,给出了基于NFRs的SA演化模型。     

基于Petri网的软件动态演化的一致性分析

在分析软件动态演化面临的挑战的基础上,以扩展的Petri网为主形式化工具,基于面向动态演化的SA元模型DEAM,对如何保证动态演化的一致性问题进行分析。首先,讨论了一致性分析的总体思路和策略,确定以构件作为动态演化实施和分析的基本对象;其次,从构件结构演化的视角对构件的子网类型进行分析,提出了保证结构一致性的方法;再次,从构件行为演化的视角,分别从内部和外部观察构件演化前后的行为,并通过建立模拟关系来分析和判断演化前后构件的行为是否一致;最后,通过案例研究对所提方法的可行性进行验证。     

基于复合信息矩阵的软件体系结构演化波及效应分析

演化性是软件的基本特性之一。软件演化由一系列复杂的变化活动组成。本文从宏观层面入手，以软件体系结构（software architecture，SA）作为软件的蓝图和支撑，设计了复合信息矩阵模型，作为软件体系结构演化波及效应分析的新工具。结合矩阵特性、图论知识和算法设计，新模型可以对一般SA静态和动态演化中的波及图表1效应进行理论分析和量化界定，弥补了现有研究模型需要简化连接器和无法评估连接器影响的不足，从而为SA演化的利用和评价提供了更为全面的依据，并为基于矩阵变化的SA演化计算机自动处理提供了新的理论支持。     

基于可达矩阵的软件体系结构演化波及效应分析

构造性和演化性是软件的两个基本特性.软件演化由一系列复杂的变化活动组成.软件演化的复杂性决定了对软件演化的研究首先应从宏观层面入手.软件体系结构SA作为软件的蓝图和支撑骨架,为人们宏观把握软件的整体结构和软件演化提供了一条有效的途径.描述了SA的构件--连接件模型,建立了SA关系矩阵和可达矩阵,凭借矩阵变换与运算对SA演化中的波及效应进行了深入的分析和量化界定;并对演化中的构件删除、增加和修改以及构件的合并与分解等变化活动所引起的各种波及效应给予了阐述;同时,给出了构件在SA中贡献大小相对量的计算方法.为SA演化的管理、控制、利用和评价提供了可靠的依据,并为基于矩阵变换的SA演化的计算机自动处理奠定了基础.     

演化电路的故障自修复设计与实现

为进一步提高电子系统在恶劣环境下的生存能力,对采用虚拟可重构电路(VRC)技术的演化电路进行电路自修复研究。根据VRC技术,建立一个可用于数字电路演化的门级电路模型,设计二进制的染色体编码。给出实现电路自主修复的工作流程,探讨进行电路故障诊断和修复的途径。在直流无刷电机控制电路中模拟宇宙单粒子烧毁逻辑门产生常见的SA错误,使电机不能正常运转。通过在线演化方法,绕过错误单元使得电机恢复转动。实验结果证明,使用演化方法可以有效解决电路中的SA故障,提高电路的可靠性。     

基于随机搜索规则的软件体系结构层性能演化优化方法

已有的基于规则的软件体系结构(Software Architecture,SA)层性能优化方法大多未充分考虑优化过程中各规则的改进幅度、使用次数和使用顺序的不确定性,导致了搜索空间受限而难以获取更优的性能改进方案。针对该问题,基于SA层性能改进策略定义一组随机搜索规则,以增大各规则的性能改进空间;在此基础上考虑这些规则的不同使用顺序和不同使用次数的组合情况,构建SA层性能优化模型RRPOM,并设计演化求解算法,进而形成一种SA层性能优化方法RRMO4PO。与已有方法在WebApp应用案例上的实验对比表明,该方法在使用更少的规则、更少次修改SA元素而获取更好可解释性的同时,有效减少了系统响应时间和改进代价。在最好的情况下,平均使用有改进效果的规则的次数和平均修改SA元素的次数较已有方法分别降低了33.3%和52.9%,与此同时将系统响应时间和改进代价分别降低了30.5%和73.6%。     

基于构件运算的软件体系结构及其复杂性度量

为了达到对软件体系结构SA的描述目标,引进了基于消息的5种构件组合运算,并给出了基于这些运算的SA的图形与其代数表达式之间的转换算法。为了降低SA复杂性,给出SA的直观复杂性度量方法,提出了11种构件演化运算,并给出了一个实例。     

基于观察者的动态演化一致性研究

为了解决软件体系结构动态演化的不一致性问题,提高软件体系结构动态演化的演化效率,针对构件技术特性,分析了软件演化技术研究现状优缺点以及观察者技术特点,结合观察者技术特点扩展了构件,使构件具有被监视以及监视的特性,提出基于观察者的动态演化模型,来保证动态演化的一致性,并为分布式环境下的动态演化提供可行的方法。     

基于改进堆叠自动编码机的垃圾邮件分类

针对堆叠自动编码机(SA)容易产生过拟合而降低垃圾邮件分类精度的问题,提出了一种基于动态dropout的改进堆叠自动编码机方法。首先分析了垃圾邮件分类问题的特殊性,将dropout算法引入到堆叠自动编码机算法中;同时,根据传统dropout算法容易使部分节点长期处于熄火状态的缺陷,提出了一种动态dropout改进算法,使用动态函数将传统静态熄火率修改为随着迭代次数逐渐减小的动态熄火率;最后,利用动态dropout算法改进堆叠自动编码机的预训练模型。仿真结果表明,相比支持向量机(SVM)和反向传播(BP)神经网络,改进的堆叠自动编码机平均准确率达到了97.66%,各个数据集上马修斯系数都大于89%;与传统堆叠自动编码机相比,改进的堆叠自动编码机的马修斯系数在Error1~6数据集上分别提高了3.27%、1.68%、2.16%、1.51%、1.58%、1.07%。实验结果表明,基于动态dropout算法的改进堆叠自动编码机具有更高的分类精度和更好的稳定性。     

Situational awareness ability and cognitive skills training in a complex real-world task

Successful performance in complex dynamic environments depends on domain-dependent factors, such as situational awareness (SA). Underlying SA in a domain are domain-independent cognitive abilities in perception, memory, attention and executive control. Individuals with lower underlying ability perform relatively poorly in complex dynamic real-world tasks. The first experiment examined whether cognitive skills training could overcome limitations in underlying SA ability that impact on complex dynamic task performance. Participants were taught a mix of cognitive management strategies (e.g. divided and focused attention and visual search) in a simulated air traffic control task. A second experiment investigated the link between underlying SA ability, TRACON and SAGAT, a widely used measure of domain-specific SA. In a third experiment, the focus was on encouraging participants to plan ahead and consider the interrelations of elements (aircraft) in the environment. Whilst both training methods ameliorated the negative impact that lower SA ability had on complex dynamic task performance, the results of the third study indicated that this may have been achieved through improved planning behaviour. Finally, participants with higher underlying SA ability performed well irrespective of training condition.     

Situational awareness ability and cognitive skills training in a complex real-world task

Successful performance in complex dynamic environments depends on domain-dependent factors, such as situational awareness (SA). Underlying SA in a domain are domain-independent cognitive abilities in perception, memory, attention and executive control. Individuals with lower underlying ability perform relatively poorly in complex dynamic real-world tasks. The first experiment examined whether cognitive skills training could overcome limitations in underlying SA ability that impact on complex dynamic task performance. Participants were taught a mix of cognitive management strategies (e.g. divided and focused attention and visual search) in a simulated air traffic control task. A second experiment investigated the link between underlying SA ability, TRACON and SAGAT, a widely used measure of domain-specific SA. In a third experiment, the focus was on encouraging participants to plan ahead and consider the interrelations of elements (aircraft) in the environment. Whilst both training methods ameliorated the negative impact that lower SA ability had on complex dynamic task performance, the results of the third study indicated that this may have been achieved through improved planning behaviour. Finally, participants with higher underlying SA ability performed well irrespective of training condition.     

复杂网络中社区发现方法的研究

研究复杂网络中社区发现方法对分析复杂网络的拓扑结构和层次结构、理解社区的形成过程、预测复杂网络的变化趋势、挖掘复杂网络蕴含的规律特征具有十分重要的意义。同时,复杂网络社区发现方法在众多实际领域还有广泛的应用前景。综述了复杂网络社区发现方法的研究现状,将社区发现方法分为无重叠社区发现、重叠社区发现、演化发展社区发现三个方面,并分析比较了算法时间复杂度和准确度。试图为社区发现方法的研究工作提供有益的帮助和参考。     

Simulated annealing heuristics for the dynamic facility layout problem

In today's economy, manufacturing plants must be able to operate efficiently and respond quickly to changes in product mix and demand. Therefore, this paper considers the problem of arranging and rearranging (when there are changes between the flows of materials between departments) manufacturing facilities such that the sum of the material handling and rearrangement costs is minimized. This problem is known as the dynamic facility layout problem (DFLP). In this paper, two simulated annealing (SA) heuristics are developed for the DFLP. The first SA heuristic (SA I) is a direct adaptation of SA to the DFLP. The second SA heuristic (SA II) is the same as SA I with a look-ahead/look-back strategy added. To test the performance of the heuristics, a data set taken from the literature is used in the analysis. The results obtained show that the proposed heuristics are very effective for the dynamic facility layout problem.     

基于XYZ/ADL的电梯控制系统体系结构的描述与求精

研究软件体系结构的首要问题是如何描述体系结构模型;运用XYZ/ADL描述软件体系结构模型,可以在统一时序逻辑框架下描述系统静态语义到实现之间不同抽象层次的规范,便于体系结构的逐步求精及相关性质分析;以电梯控制系统为例,运用XYZ/ADL形式化地描述了系统体系结构的风格、静态模型和动态模型,并对体系结构模型的主要组件进行了逐步求精,使系统的体系结构从最初的总体功能规范平滑地过渡到了最终的可执行程序;研究表明:形式化描述语言XYZ/ADL在实时控制系统的开发中有着重要的实践意义。     

A simulated annealing algorithm for dynamic layout problem

Increased level of volatility in today's manufacturing world demanded new approaches for modelling and solving many of its well-known problems like the facility layout problem. Over a decade ago Rosenblatt published a key paper on modelling and solving dynamic version of the facility layout problems. Since then, various other researchers proposed new and improved models and algorithms to solve the problem. Balakrishnan and Cheng have recently published a comprehensive review of the literature about this subject. The problem was defined as a complex combinatorial optimisation problem. The efficiency of SA in solving combinatorial optimisation problems is very well known. However, it has recently not been applied to DLP based on the review of the available literature. In this research paper a SA-based procedure for DLP is developed and results for test problems are reported.

Scope and purpose

One of the characteristic of today's manufacturing environments is volatility. Under a volatile environment (or dynamic manufacturing environment) demand is not stable. To operate efficiently under such environments facilities must be adaptive to changing demand conditions. This requires solution of the dynamic layout problem (DLP). DLP is a complex combinatorial optimisation problem for which optimal solutions can be found for small size problems. This research paper makes use of a SA algorithm to solve the DLP. Simulated annealing (SA) is a well-established stochastic neighbourhood search technique. It has a potential to solve complex combinatorial optimisation problems. The paper presents in detail how to apply SA to solve DLP and an extensive computational study. The computational study shows that SA is quite effective in solving dynamic layout problems.