并行处理技术在雷达数据处理中的应用研究

为了解决雷达数据处理系统数据量日益增大,计算能力逐渐不足的问题,提出两种并行处理方法。第一种方法是对数据处理各步骤中的循环采用多个线程并行处理,属于细粒度并行;第二种方法是根据雷达数据的局部性特征,把雷达探测空域按照径向距离划分成多个部分,由多个子任务并行处理,属于粗粒度并行。实验结果显示,4线程细粒度并行雷达数据处理架构性能是原来的3倍,4任务粗粒度并行架构性能是原来的5倍,证明并行处理技术在雷达数据处理中的有效性,并且任务级的粗粒度并行架构更适合雷达数据处理。     

基于多核DSP的MIMO雷达信号处理的实现

针对MIMO雷达多通道回波信号处理的同步性和实时性需求,在分析MIMO雷达信号处理的特点及多核DSP硬件结构的基础上,提出了一种基于多核处理器TMS320C6678的并行实现方法,并解决了使用过程中的诸多关键技术。该方法实现了多任务并行处理和高效通信。实验结果表明,该方法在较小规模的硬件平台上实现了较低功耗且高实时性的应用。     

一种双核并行处理网络化数据采集系统设计

为满足某型飞机防失速改出伞系统的瞬态电气参数测试需求,构建了以双核工业控制计算机和高速数据采集卡为核心,以LabWindows/CVI为虚拟仪器软件开发平台的多线程多任务实时数据采集系统;通过操作系统内核,系统采用双核并行处理方式,完成了高实时性和大数据吞吐量的多通道数据实时采集,并通过TCP/IP和ODBC接口进行了远程测控和数据库管理;系统实现了LabWindows/CVI下的多线程机制及其同步技术,双核并行处理技术,TCP/IP通信技术;经实验证明该系统实时性高,准确可靠。     

基于Windows XPE的水下航行器航行操纵系统多任务软件设计

航行操纵系统是水下航行器控制系统的重要组成部分;为了保证航行操纵系统的实时性与可靠性,鉴于其硬件板卡驱动支持Windows平台,故软件采用了一种基于Windows XPE实时嵌入式系统的设计方法,根据操纵要求对航行操纵系统实时多任务进行了划分,诸如手柄信息处理任务、自动控制任务和网络通信任务等,介绍了多任务执行实体—线程(thread)的优先级的设置和线程同步工具的选取,并分析了Windows的多线程调度策略,然后详细阐述了航行操纵系统各任务的执行流程以及实现方法;最后,对航行操纵系统进行了实验室仿真测试,结果表明该系统实时性和控制精度达到了设计要求,操纵系统性能良好.     

基于CUDA和电子海图模拟雷达岸线回波的方法

雷达回波信号的仿真是雷达模拟器模拟显示逼真与否的基础,在此背景下提出利用电子海图和CUDA并行处理技术,模拟导航雷达海岸线回波的新方法.通过对电子海图的并行处理实现对导航雷达海岸线回波的模拟,仿真了雷达岸线回波的遮挡效果,解决了雷达模拟器回波生成实时性要求的难题.通过计算机仿真验证了该方法的有效性,已实际运用于某型雷达模拟器的回波信号仿真.     

基于千兆以太网的雷达数据可靠传输系统设计

为了实现雷达数据长距离高速可靠传输,该文介绍了基于千兆以太网的雷达数据实时高速可靠传输方案。该方案充分利用了FPGA并行处理、灵活性高的特点,集成实现了两路千兆以太网控制器(MAC),用来并行传输雷达数据,从而提高了数据传输速率;还实现了数据包的校验出错重传机制,确保数据接收端收到正确的数据包,保证了雷达数据的高速长距离可靠传输。     

应用多线程并行机制实现大规模三维场景绘制

针对大规模三维场景可视化问题 ,提出了以数据分割、动态调度和多线程并行处理为主要思想的解决方案 ,并重点对多线程并行处理方法进行了研究 ,提出通过合理协调 I/O线程与绘制线程的分工及同步 ,更加充分利用机器的计算资源 ,以获得最佳的绘制效果 .文中通过具体应用的实例证明了该并行处理方法的有效性     

天气雷达组网拼图并行处理方法研究

天气雷达组网拼图并行处理的目的就是为了满足实时业务的需求,通常的串性方法在雷达运行的六分钟周期内不能完成。利用共享存储多核处理器的高性能服务器,研发了高频度实时全国天气雷达资料处理的并行计算系统,根据单部天气雷达处理和多部雷达拼图的特点,提出了进程级别和线程级别细粒度的OpenMP共享内存编程的两级并行方法,给出一个合理的派生线程粒度数,同时利用共享内存文件的方法提高程序的执行效率。实验结果表明,使用两级的并行计算等方法可以满足全国天气雷达实时处理的要求。利用并行计算实现实时性要求高的业务系统是重要的手段。     

天气雷达组网拼图并行处理方法研究

天气雷达组网拼图并行处理的目的就是为了满足实时业务的需求,通常的串性方法在雷达运行的六分钟周期内不能完成.利用共享存储多核处理器的高性能服务器,研发了高频度实时全国天气雷达资料处理的并行计算系统,根据单部天气雷达处理和多部雷达拼图的特点,提出了进程级别和线程级别细粒度的OpenMP共享内存编程的两级并行方法,给出一个合理的派生线程粒度数,同时利用共享内存文件的方法提高程序的执行效率.实验结果表明,使用两级的并行计算等方法可以满足全国天气雷达实时处理的要求.利用并行计算实现实时性要求高的业务系统是重要的手段.     

并联机器人仿真运动控制的多线程实现

现代运动模拟器对响应快速性、跟踪准确性等仿真运动特性提出了更高要求,使得并联机器人机构的运动控制更为复杂。以某型潜艇操纵模拟器为例,其控制软件采用模块化设计,利用NT环境下多线程技术,结合多媒体定时器、普通定时器,实现软件的洗出滤波、运动学反解、运动信息发送、安全保护等多任务的有机调度。在外控线程中建立网络数据接收、数据处理、液压缸控制信息发送等三个子线程,将它们从外控线程中分离出来,大大提高了数据传输和处理及运动控制的实时性和可靠性。     

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。