杂交粒子群算法在列车运行调整中的应用研究

针对列车运行调整存在约束条件多、求解难度大等问题, 结合城市轨道交通列车运行特点, 建立了优化的列车运行调整模型。在此基础上, 引入遗传算法中的杂交思想, 采用改进后的粒子群算法对此模型进行求解, 给出了求解算法的具体步骤, 并采用西安地铁2号线数据进行仿真验证。结果表明, 采用杂交粒子群算法解决列车运行调整问题是一种有效的方法, 并且其优化能力优于标准粒子群算法。     

基于收敛粒子群算法的重载铁路列车运行调整方法

针对施工天窗对重载铁路行车安全限速和行车安全产生的不良影响,提出了基于收敛粒子群算法的重载铁路列车运行调整方法。首先,在分析列车追踪间隔影响因素的基础上,推导出不同编组类型重载列车之间的追踪间隔计算公式,实现了重载列车追踪间隔计算。然后,考虑施工天窗后的限速要求,以重载列车总晚点时间为优化目标,以列车区间最少运行时分、追踪间隔时分、列车停站时分、天窗时间段内禁止行车、天窗后安全限速等为约束条件,建立了施工条件下重载铁路列车运行调整模型,刻画了考虑安全限速的重载列车运行调整问题。通过优化列车到站、离站以及通过车站时刻,实现重载列车运行调整。进而,针对模型特点,在经典粒子群算法中引入收敛因子,设计了收敛粒子群算法对模型进行求解。最后,以朔黄铁路运输生产数据为基础,对建立的重载铁路运行调整模型进行实例化处理,验证了模型和算法。实验结果表明,对于求解重载铁路运行调整问题,设计的收敛粒子群算法比经典粒子群算法在计算效率上提升了5.45%,而求解精度保持不变。该方法可压缩重载列车追踪间隔,提高重载铁路运输效率,保证行车安全,提高基于安全限速的列车运行调整效率,为施工条件下重载铁路列车运行调整工作提...     

基于粒子群算法的列车运行调度研究

列车运行调度是铁路行车调度指挥工作的重要内容,其计算机自动计算求解问题是我国铁路信息化建设的核心技术和难点。建立了高速列车运行调度的数学模型,采用粒子群算法求解。设计的算法步骤是,将列车运行调整问题描述成适合粒子群算法的形式,确定该问题的适应度函数,对基本问题模型进行改进,进而确定运动方程。以京广高速铁路线路内具有6个车站的下行方向,运行14列列车为例,利用设计的粒子群算法求解了某干扰条件下的列车运行调度问题,为列车运行调整提供了新的方法。     

基于两阶段算法的列车调度问题

考虑突发铁路损坏对列车运行的影响, 在列车运行调度理论的基础上, 建立了单线铁路调度模型, 设计了一种带有突发事件处理能力的两阶段列车调度算法, 第1阶段对列车区间运行速度进行调整, 第2阶段对列车的停站时间进行调整. 将3种有效的搜索算子、一种自适应更新规则与粒子群算法相结合, 以列车延迟率作为优化目标, 求解单线铁路列车调度问题. 通过将所提算法与其他算法在相同实验条件下进行测试对比, 并进行突发事件测试, 验证了所提算法的有效性.     

基于二进制粒子群优化的一个最小属性约简算法

研究基于二进制粒子群优化算法思想求解决策表最小属性约简问题的方法.定义适当的适应值函数,将决策表最小属性约简问题转化为一个适合二进制粒子群优化算法求解的0-1组合优化问题,证明问题解的等价性.在此基础上,引入种子粒子概念及其自适应保护策略,提出一个改进的二进制粒子群算法,取得良好的效果.实验结果说明该算法的有效性.     

面向列车运行调整问题的粒子群算法研究*

列车运行调整问题是一种特殊的NP完全问题,不仅具有众多约束,并且有着列车等级要求和延迟传播限制,使得该问题搜索空间庞大,可行解范围狭小,往往难以获得较优解。为求解列车运行调整问题,针对此特殊性,将捕食搜索策略思想引入到粒子群算法中,并在此基础上提出一种速度限制的调整方式,同时辅以自适应控制,使得算法在大范围搜索时更易跳出局部最小解,而在小范围搜索时粒子飞行速度更慢,搜索更精确。将该算法用于列车运行调整问题,所得调整方案比遗传算法和普通粒子群算法结果更逼近原开行方案。     

采用再生制动的地铁时刻表节能优化研究

地铁运行的主要成本是电能消耗,如何降低地铁运行能耗是建设绿色城市的重要课题.本文从列车运行时再生制动产生回馈电网能量出发,建立采用再生制动的地铁列车运行能耗模型.进而,将地铁运行节能问题转化为地铁列车时刻表优化问题,并引入列车运行约束和混合逻辑动态模型约束将该问题建模为一个非线性混合整数规划问题.本文设计了分解协调优化算法,以列车停站时间和发车时间间隔作为优化操作变量进行优化.从仿真结果可知,以不同的操纵变量进行优化均能有效提高再生制动能量利用率,且分解协调算法的求解结果优于传统的模拟退火算法.     

改进型PSO算法在VRP中的应用

运用罚函数法将约束优化问题转化为无约束优化问题,同时采用实数编码方案,将离散的车辆路径问题转化成准连续优化问题,在此基础上,用改进的粒子群优化算法求解最优值.改进的粒子群算法引入了杂交PSO模型和变异算子.仿真实验结果表明,该算法在保持粒子种群多样性、提高收敛速度和搜索精度、扩大搜索范围、避免过早收敛于局部极值点等方面...     

单线列车调度问题的双向阻塞车间调度模型及其粒子群求解算法

针对单线列车调度问题的特点,以线路中列车的总运行时间最小为目标,建立了可以直观描述问题解空间的双向阻塞车间调度模型,并提出了一种有效的离散粒子群优化算法进行求解。该算法基于双向阻塞车间调度模型设计了排列编码形式,从而可确定列车的运行顺序,同时利用随机策略和运行时间最短优先策略选择列车运行轨道;算法在求解过程中,提出了列车冲突的检测和化解方法,并按照“调度-检测冲突-化解冲突”的步骤逐区段调度列车运行;最后,利用离散粒子群优化算法进行全局优化,得到问题的最优解。仿真实例表明,所得模型和算法能够高效地求解单线列车调度问题。     

低碳约束下冷链物流配送共享仓选址多目标优化方法

针对当前冷链物流配送中心选址模型存在选址不合理、选址过程复杂,导致资源浪费和经济成本增加的问题,提出在低碳约束下,构建一个基于低碳约束冷链物流配送共享仓中心选址和路径优化模型,在粒子群算法的基础上,分别加入免疫算法和粒子群算法,得到改进免疫粒子群算法和混合粒子群算法,通过这两种算法分别实现共享仓中心选址求解快速寻优和多目标优化,以提升模型的路径优化能力和鲁棒性。实验结果表明,提出的方法改进免疫粒子群算法可在不同约束条件下实现冷链物流配送共享仓快速选址,且选择位置寻优求解速度提升;同时通过混合粒子群算法可实现物流路径优化,规避路径缺陷,从而提升路径优化能力,实现多目标优化路径的准确选址。     

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.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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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