基于任务综合规划的相控阵自适应调度方法

研究机载相控雷达调度优化控制问题.机载相控阵雷达可以高效遂行作战任务,但如何合理调度雷达任务请求,实时优化处理同时多任务对系统时间资源的竞争,是充分发挥多功能相控阵雷达性能优势的关键.针对相控阵雷达同时多任务在时间窗约束下实时优化调度问题,在综合考虑调度时刻前后任务请求、调度限制和可用资源等因素基础上,权衡任务请求重要程度、紧急程度和前后一定时间段内资源利用情况,提出了一种利用任务综合规划的相控阵自适应调度算法.仿真结果表明,新算法能够在雷达有限时间资源内提高相控阵雷达任务调度效率和时间利用率,获得了更优的综合性能.     

基于改进时间指针的相控阵雷达任务调度方法

针对相控阵雷达实时任务调度中时间资源利用不充分的问题,提出了一种基于改进时间指针的任务自适应调度方法.以时间指针为对象,从整个调度时间轴上所有满足时间指针处执行条件的任务请求中,选择一个优先级最高的任务作为当前时刻的执行任务,有效减少了空闲时间的浪费,使得相控阵雷达能够在有限时间资源内调度执行更多的任务.与基于传统时间指针的调度方法仿真对比,结果表明:方法提高了任务调度成功率和时间利用率,有效提升1了相控阵雷达的整体调度性能,具有一定的优越性.     

直升机载相控阵雷达波束波形联合自适应调度算法研究

孔径分割技术和波形捷变能力让直升机雷达可同时形成多个波束完成不同功能,并根据不同需求选择不同波形,因此对雷达资源管理提出更高的要求;综合考虑时间资源、能量资源、孔径资源的约束下,提出一种适合于多子阵直升机载相控阵雷达的波束波形联合自适应调度算法,对雷达波束和波形进行有效调度,并通过与传统自适应调度算法进行仿真对比,证明了该算法在调度能力、能量节约等方面的先进性。     

一种基于IMM的自适应目标跟踪算法研究

对目标进行自适应跟踪是节约雷达资源的途径之一.以相控阵雷达为基础研究了一种目标自适应跟踪算法.介绍了传统连续情况下的周期采样方法,通过设定上、下界来限制算法中采样周期的变化.并在连续采样的基础上给出一种改进的离散采样算法,改进算法通过比较滤波残差和量测误差设定一组离散采样值,计算量减小,跟踪误差降低.基于IMM对两种自适应采样算法以及固定周期采样算法进行Monte Carlo仿真对比,仿真结果表明两种自适应采样算法均大大降低了采样宰,改进的离散自适应采样算法跟踪性能相对较好.     

相控阵雷达系统功能仿真及应用

在国土防空预警网优化问题的研究中,相控阵雷达具有频率捷变等特点和多目标跟踪能力,是构成国土防空预警网的重要组成部分.以雷达组网、组网雷达资源管理及相关算法测试为背景,嵌入到雷达组网仿真平台中并获得实测数据,提供了一种相控阵雷达功能仿真方法,重点讨论了波位编排、目标检测和相控阵雷达的任务调度算法等模块的实现.最后仿真系统对三个普通目标以及一个隐身目标在雷达扫描空域的搜索、验证、跟踪、失跟等雷达事件进行了仿真结果分析,验证了相控阵雷达系统和相关算法的有效性.     

基于改进时间窗的相控阵雷达跟踪任务调度方法

针对相控阵雷达目标跟踪过程中的任务调度问题,提出了一种基于改进时间窗的任务调度方法.该方法兼顾相控阵雷达对目标的正常跟踪和对任务的充分调度,根据目标跟踪滤波中的残差和雷达对目标的跟踪波门之间的约束关系,并结合目标的飞行方向,实现对目标跟踪任务的提前时间窗和延迟时间窗的区别计算.最后将该方法与传统的时间窗设计方法进行对比仿真,仿真结果表明,该方法既降低了目标失跟率,又保证了较高的任务调度成功率,有效提升了相控阵雷达整体调度性能,具有一定的优越性.     

基于自适应脉冲间隔的火控雷达目标跟踪技术

为了能在提高雷达生存能力的同时,保持雷达的跟踪能力,提出一种基于自适应脉冲间隔的目标跟踪技术。给出火控雷达的信号模型及其改进的时域信号,分析基于匀加速运动模型的扩展卡尔曼滤波算法,研究脉冲间隔的自适应变化规律及信号的截获概率。仿真结果表明,该技术能准确跟踪目标,延长信号截获时间,从而降低侦察系统对火控雷达的截获概率。     

相控阵雷达相参积累工作模式下的能量调度策略

为了优化相控阵雷达在相参积累工作方式下的能量调度和分配,实现多目标高效搜索和稳定跟踪,提出了相控阵雷达相参积累工作模式下的能量调度策略。基于相参积累工作模式下的最远可探测距离与积累时间的变化关系,分析了相控阵雷达相参积累工作方式下的空域搜索能力和多目标跟踪能力,设计了多目标跟踪和边搜索边跟踪模式下的能量调度与分配策略。结果表明,虽然相控阵雷达在相参积累工作模式下并不适合大范围固定空域搜索,但在可靠的数引信息引导和合适的能量调度方案下,仍可实现波束间多目标的可靠搜索与稳定跟踪。     

相控阵测量雷达扫描特性及误差补偿方法研究

基于相控阵雷达工作原理,分析了天线扫描对波束宽度和天线增益的影响;以往只考虑相控阵雷达电扫法线跟踪测量精度,未考虑相控阵雷达偏轴电扫跟踪测量精度;通过雷达步进偏轴跟踪模拟目标方法,采集雷达角度补偿数据库,实现了偏轴扫描跟踪角度误差补偿;试验结果表明,该补偿方法能够提高相控阵雷达偏轴扫描跟踪坐标测量精度。     

有源压制干扰下的相控阵雷达多目标跟踪时间资源优化配置算法

针对有源压制干扰下的相控阵雷达（Phased array radar, PAR）多目标跟踪时间资源优化配置问题,提出了一种基于互信息（Mutual information, MI）的配置算法。采用MI准则作为目标跟踪性能量化指标,推导了包含时间变量的雷达回波与路径增益矩阵MI表达式,建立了时间资源优化配置模型,并采用改进的遗传算法实现了模型求解。仿真结果表明,该算法能在有源压制干扰条件下最大化有效跟踪目标数,并提高有效跟踪目标的整体跟踪性能。     

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