求解旅行商问题的混合蚂蚁算法

旅行商问题是一个经典的NP问题，文中给出了一个有效的求解旅行商问题的混合蚂蚁算法。算法设计了初始信息素量设置方案和信息素的更新方法，限制了蚂蚁转移的目标城市数，并使用2-Opt方法对路径进行优化。数据实验表明，该算法是有效的。     

基于邻域搜索的改进最大最小蚁群算法

针对蚁群算法求解旅行商问题时易陷入局部最优的问题,提出一个改进的混合最大最小蚁群算法,并应用于求解旅行商问题.上述算法设计了一种新的信息素更新模型,单个蚂蚁每走一步就进行信息素局部更新,在所有的蚂蚁搜索一周后,最优路径蚂蚁进行全局信息素更新.提出一种新的邻域搜索模型,将邻域大小设置为原来的一半,提高了计算的效率.在每个蚂蚁的一个周期循环后,使用邻域搜索算法优化最优解的路径长度.仿真结果表明,改进算法具有较高的求解精度和收敛速度.     

增强型的蚁群优化算法

旅行商问题是一个NP-Hard组合优化问题。根据蚁群优化算法和旅行商问题的特点,论文提出了对蚁群中具有优质解的蚂蚁个体所走路径上的信息素强度进行增强的方法,并同其他的优化算法进行了比较,仿真结果表明,对具有全局和局部最优解的个体所走路径上的信息素强度进行增强的蚁群优化算法比标准的蚁群优化算法和其他优化算法在执行效率和稳定性上要高。     

基于T-ACO算法的旅行商问题求解优化研究

为了有效求解旅行商问题,本文提出了一种基于T分布的改进蚁群算法。针对基本蚁群算法易陷入局部最优、寻优精度低等缺陷,在优化过程中,在信息素更新原则上,引入T分布,有益于基本蚁群算法弥补其不足。在基本蚁群算法中增加了信息素的突变,使得蚂蚁群的多样性提高,从而跳出局部最优的限制。与此同时,T-ACO算法在旅行商问题搜寻精度与收敛速度方面也得到了提高。对T-ACO求解旅行商问题的性能进行了实验仿真,实验分析表明,T-ACO算法有更好的寻优能力。     

基于混合信息素递减的蚁群算法

根据蚁群算法信息素更新的特性,提出了求解旅行商问题的混合信息素递减的蚁群算法。把基本蚁群的三种不同的信息素更新方式混合在一起,同时提出了信息素递减更新的方法。新的更新方式避免了蚂蚁在寻找最优解的过程中,由于禁忌表元素的逐渐增加而限制蚂蚁巡游路径选择的缺点,减少了巡游后期信息素对于后继蚂蚁的影响,提高了后继蚂蚁的巡游质量。仿真实验表明了该混合算法的有效性。     

求解旅行商问题的混合量子蚁群算法

针对蚁群算法求解旅行商问题时易陷入局部最优和收敛速度慢的问题,提出一种新的求解旅行商问题的混合量子蚁群算法。该算法采用量子比特的概率幅对各路径上的信息素进行编码,采用量子旋转门及蚂蚁走过的路径对信息素进行更新,设计一种新的变换邻域准则。基于TSPLIB的仿真实验结果表明了该算法具有较快的收敛速度和求解精度。     

简化蚁群算法

针对最大最小蚂蚁系统中信息素下界难以确定以及算法性能易受同构问题影响的缺点,提出一种简化蚁群算法.信息素的上下界被限制在一个固定的区间内,不随目标函数值的更新而改变;信息素的更新量是一个与具体目标函数值无关的常数.所提出的简化算法不仅具有强不变性和平移不变性,而且算法的性能不受信息素下界的影响.针对旅行商问题的仿真实验验证了改进算法的可行性和有效性.     

基于信息素变异的蚁群算法的应用研究

针对基本蚁群算法的不能更好地模拟真实蚂蚁觅食和局部收敛等现象,提出一种用于求解旅行商问题（TSP）的改进蚁群算法,该算法将信息素的更新与挥发算法做了改进,从而能够更好的模拟真实蚂蚁,并且有效的提高了搜索效率。仿真结果证明了该算法的有效性和可行性。     

蚁群与粒子群混合算法求解TSP问题

旅行商问题（TSP）是最古老而且研究最广泛的组合优化问题。针对TSP问题,提出一种蚁群与粒子群混合算法（HAPA）。HAPA首先将蚁群划分成多个蚂蚁子群,然后把蚂蚁子群的参数作为粒子,通过粒子群算法来优化蚂蚁子群的参数,并在蚂蚁子群中引入了信息素交换操作。实验结果表明,HAPA在求解TSP问题中比传统算法和同类算法更具优越性。     

一种快速求解旅行商问题的蚁群算法

蚁群优化是一种元启发式的随机搜索技术,是目前解决组合优化问题最有效的工具之一.将信息素更新和随机搜索机制的改进相结合,提出一种快速求解旅行商问题的蚁群算法.首先给出了一种新的信息素增量模型,以体现蚂蚁在不同路径上行走时所产生的信息素差异;然后以蚂蚁经过的路径(直线段)作为信息素扩散浓度场的信源,改进了信息素扩散模型,强化了蚂蚁间的协作和交流;最后采用较低复杂度的变异策略对迭代的结果进行优化.在大量通用数据集上的实验表明,该算法不仅能获得更好的最优解,而且收敛速度有显著的提高.     

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