基于改进蚁群算法的无人机动态航路规划

研究无人机航路规划,针对基本蚁群算法易于陷入局部最优、规划航路耗时长的问题,对基本蚁群算法进行了改进;引入航路点的动态自适应选择策略和信息素挥发因子动态自适应调整准则,有效克服了基本蚁群算法的不足,并对规划出的航路进行了平滑处理,使其更加满足无人机实际飞行需求;通过仿真分别规划出无人机在静态威胁和动态威胁中的航迹,仿真结果表明,与基本蚁群算法和遗传算法相比,改进的蚁群算法在两种飞行环境中均能规划出较优的航路。     

QPSO在无人机侦察航路规划中的应用研究

对于侦察区内的防空威胁和目标分布情况,对飞行航路预先规划,可以减小被敌方发现和飞行距离,从而显著提高UAV侦察效率.在研究了粒子群算法的基础上,提出了具有量子行为的粒子群算法,并首次将该算法应用于无人机航路规划.目标函数主要考虑地面防空威胁与飞行距离这两个主要因素,并给出了航路规划的方法和步骤,该算法很好的解决了粒子群算法局部极值问题.实验结果表明,QPSO算法收敛快,得到的侦察航路较优,且很好的对威胁进行回避,能有效满足无人机飞行任务规划的要求.     

优化蚁群算法在无人机航路规划中的应用

研究无人机航路规划问题,采用基本蚁群算法易陷入局部最优、搜索时间长导致人机作航路规划效率低的难题.为了提高无人机航路规划效率,提高速度和系统品质特性,提出了一种基于改进蚁群算法的无人机航路规划方法.算法前期采用了保留最优解和自适应航路点选择策略对路径进行优化,使之适应大规模问题求解;后期改进了基本蚁群算法中信息素、挥发因子的更新规则,通过改进使得每轮搜索后信息素的增量能更好地反映求解的质量,有效地避免陷入局部最优,加快了收敛,提高了搜索效率.采用改进的蚁群算法对无人机任务航路进行仿真,仿真结果表明,改进方法避免了陷入局部最优,并缩短了搜索时间,航路规划效率明显提高,证明是一种有效的无人机航路优化方法,可为实际应用提供参考.     

基于混合多种群自适应蚁群算法的无人机航路规划

针对基本蚁群算法在航路规划中易于过早陷入局部最优解,对蚁群算法进行了改进;提出了具有多种群的蚁群算法,并将导引因子引入到状态转移策略中,减少蚂蚁局部搜索的盲目性,确保蚂蚁最终完成航路搜索;当算法陷入局部收敛时,通过交换各种群的信息素,并对每个种群的挥发系数进行自适应调整,从而扩大了搜索空间,提高了搜索全局性;最后在代价函数简化后的栅格图中对改进算法进行了仿真;仿真结果表明,该方法可以有效防止算法陷入局部最优,是一种有效的航路规划方法.     

基于转角约束的改进蚁群优化算法路径规划

针对传统蚁群优化（ACO）算法搜索路径时易陷入局部最优、路径过长、转弯角度过大等问题,提出一种基于转弯角度约束的改进ACO算法。首先,增加起始点与目标点之间区域的初始信息素浓度,以避免初期盲目搜索;然后,在启发函数中加入A^*算法的估价函数和转弯角度因子,以便在下一步选择路径长度和转角次数综合最优的节点;最后,在信息素更新部分引入狼群算法的分配原则,来加强优质种群的影响力,同时借鉴最大最小蚁群（MMAS）算法进行信息素浓度的限制,从而避免算法陷入局部最优。Matlab仿真结果表明,改进算法与传统ACO算法相比,规划出的路径长度缩短了13.7%,转弯次数减小了64.3%,累计转弯角度减少了76.7%。实验结果表明,所提改进算法能有效解决全局路径规划问题,避免了移动机器人过多的能耗损失。     

基于生物地理学优化的多UCAV协同航迹规划

研究多无人机协同路径规划问题,为了获取从起始点到达目标点,能够避开各种阻碍的最优运动路径,提出了一种基于BBO的多UCAV协同航迹规划方法.通过对地形环境、航迹表示方式进行描述,将生物地理学优化算法运用于多UCAV协同航迹规划,对约束条件及威胁进行分析,建立了UCAV航迹规划模型及多UCAV协同航迹规划模型;对BBO算法适宜度向量编码及迁徙模型进行了分析,设计了相应的优化算子;最后,构建了多UCAV协同航迹规划的求解框架,并结合BBO算法开展了相应的仿真.仿真结果表明,改进方法较好地实现了多UCAV协同航迹规划的优化.     

基于改进人工蜂群算法的多无人作战飞机协同航迹规划

针对多无人作战飞机(UCAV)航迹规划约束条件复杂、不确定因素多、实时性要求高的特点,提出一种基于改进的人工蜂群算法求解多UCAV协同航迹规划模型。首先构建战场空间的改进Voronoi图生成航迹优化可飞区域;然后采用混沌搜索算法来初始化航迹集合作为算法的蜜源,使其初始航迹集合能以有限的数据充分表示航迹优化可飞区域;最后对多UCAV在多种威胁环境下的航迹空间寻优进行仿真验证。仿真结果证明改进的人工蜂群算法提高了蜜源多样性和算法的收敛速度,增强了UCAV的动态战场适应能力和突发威胁应对能力。     

对抗环境下多UCAV协同速度规划

在作战对抗环境下,由于目标威胁区域的密集排列,UCAV可能同时受到多个防空设施的威胁.为了有效优化控制飞行速度,利用威胁的火力范围和UCAV的攻击区确定各UCAV路径上的航路点,通过对各航路点之间的平均速度进行优化组合达到对整个飞行过程的速度控制,使飞行过程中所受总威胁值最小,飞行时间最接近预定值,同时满足UAV飞行特性约束,使用基于ε占优的多目标进化算法(MOEA)求解多目标优化速度.仿真结果表明算法能够对问题进行合理优化,获得一组高质量Pareto解,为决策者提供决策的依据.     

基于分层思想的无人飞行器航路规划研究

在无人飞行器航路规划问题的研究中,为提高航路规划的效率和精度,针对传统遗传算法收敛速度慢、易陷入局部最优、寻优精度较差的问题,提出了一种分层思想的解决方法.首先用链接图法描述规划环境,通过采用Dijkstra算法寻找初始最优航路,并利用航路编码技术对初始航路进行优化;然后在已有的研究成果上,提出一种集混沌优化、模拟退火、遗传算法为一体的改进遗传算法(CGASA),在解决多目标多约束优化问题时取得了较好的结果;最后综合考虑飞行器的机动性能、威胁因素、飞越目标进入角度等代价的选取,利用改进遗传算法调整导航点的位置得出了满足性能要求的航路.     

改进粒子群算法在UCAV航路规划中的应用

针对在无人作战飞机(UCAV)航路规划中存在的计算复杂和收敛性等问题,该文利用标准粒子群算法原理,在算法搜索过程中引入变异算子,克服了标准算法易陷入局部极值点的不足。利用一组正弦波曲线来构造一个粒子,通过对正弦波个数和幅值的限制,使该方法得到的飞行航路严格经过起始点和目标点,而且满足UCAV的机动性能要求。仿真结果表明该方法简便可行,粒子能较快地收敛于全局最佳航路。     

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。