双波段遥测天线设计

随着航空飞行试验数据量的不断增加,原有IRIG106遥测系统已不能完全适应当前和未来的需求;同时随着网络技术的不断发展,遥测系统的网络化成为新的发展趋势;民用4G通信占用S波段遥测资源使得航空遥测寻找新的传输频段;为了充分利用和保护现有资源,并适应遥测的网络化发展,提出在现有S波段遥测基础上增加C波段网络数据传输功能,开展双波段遥测天线设计技术研究;在对天线结构进行合理设计的基础上,提出了一体化馈源设计方案;通过S波段振子与C波段振子的集成化设计,实现了C波段无线网数据与S波段串行数据流的共同传输,极大地提高了遥测数据传输速率,缓解了遥测频率资源紧张的现状;通过飞行试验验证,设计的双波段天线能够满足飞行试验大速率数据的传输需求。     

C波段无线网络通信技术及在飞行试验遥测中应用构想

在分析国内外C波段无线网络通信研究进展基础上,结合现行飞行试验遥测中遇到的技术瓶颈,提出了将C波段无线网络通信技术应用于飞行试验遥测中的构想,建立基于C波段的无线网络的空地一体化遥测网络体系。C波段空地网络化遥测链路的建立,扩展遥测数据传输可用频段的同时增加上行通道,建立机载网络系统与地面监控网络的网络通信链路,为未来空天地一体化遥测网络的建立建立技术基础;同时利用通用的网络管理流程,对整个测试资源动态配比,提高试飞效率。     

C波段基站式多目标遥测网络构建技术

随着航空工业的不断发展,现行航空测试使用的IRIG-106标准的S波段单向点对点的PCM数据传输体制已不能满足新技术、新测试发展的需求,需要突破现有传输体制,探索数据传输新模式;文中结合美国iNET标准,选定C波段作为遥测传输频段,在成熟的网络通信技术的基础上,开展C波段基站多目标遥测网络构建技术研究,主要从架构设计、接入体制、系统研制等方面进行了研究;最后通过构建C波段基站式多目标遥测网络飞行试验演示验证系统进行了验证;验证结果表明文中设计的系统能够实现遥测数据的传输;通过C波段基站式多目标遥测网络构建技术的研究,突破了传统遥测体制,实现了基于C波段的基站式遥测数据传输,为实现高速、双向、多目标空地数据传输提供基础。     

IEEE1588时钟同步技术在飞行试验遥测网络系统中的应用

随着遥测网络系统在飞行试验遥测传输领域的发展,尤其是INET概念的提出,利用无线网络传输数据已成为飞行试验遥测发展的新方向;网络化的测试、遥测系统,对时钟同步有着很高的要求,选择合适的时钟同步协议,满足通信过程中对时间一致性的要求,成为新一代遥测网络系统的一项关键技术;以无线网实现飞行试验数据传输为基础,探讨了几种时钟同步技术在无线网传输环境下应用的优缺点,并着重研究了IEEE1588时钟同步协议的实现原理及其在遥测网络系统中实现时钟同步的方法.     

基于TDMA多目标遥测数据传输系统设计与实现

遥测监控是新机试飞提高试飞效率、保障试飞安全的重要手段,遥测数据的传输能力和传输质量决定了遥测实时监控性能的优劣;随着大量飞机同场次试飞任务的广泛开展,现有飞行试验单站点对应单目标的遥测体制存在一定的局限性,为了解决多个目标同时遥测数据传输的难题,文章在对常用的几种多目标体制进行了比较的基础上,设计了一套基于TDMA体制的多目标遥测数据传输系统,对该系统数据的传输速率、距离进行了理论计算,并进行了飞行试验验证,能够满足任务需求,有着很好的应用前景。     

改进型FQPSK的FPGA设计与实现

随着运载火箭飞行试验任务复杂程度提高以及大型运载火箭和未来重型运载火箭的研制,信息传输所需的码速率迅速提高,频谱资源越来越紧张,PCM-FM调制体制已经不满足需求.为了提高频带的利用率,论述了一种改进型的FQPSK,并且对它的性能进行了仿真分析,证明改进型的FQPSK包络恒定,缩减了包络起伏,提高了频带利用率.为了验证了其在遥测系统中实现的可行性,使用FPGA对改进型FQPSK进行了设计与实现,查表法和延时后移减小了系统的复杂度,使系统更小、具有更好的同步性.     

航空飞行试验遥测技术发展趋势与对策

以新的遥测网络技术范畴为主线,根据航空飞行试验遥测的需求变化与增长,简要介绍了当前国内外航空飞行试验遥测技术的研究与应用现状,总结了航空飞行试验遥测技术的发展趋势,分析了我国航空飞行试验遥测存在的突出问题,针对我国空地一体化遥测网络技术的发展和系统构建,提出了几点对策和建议。     

运载火箭天基遥测技术

针对我国天基测控技术的发展趋势,提出了基于S频段终端通过中继卫星进行运载火箭天基遥测,以某运载火箭发射GTO轨道任务为例,分别对天线跟踪特性和链路增益进行了分析计算,介绍了运载火箭天基遥测系统的组成,分析表明,在满足天线跟踪角和链路指标的条件下,可实现天基遥测;这些分析结论可为工程应用提供参考。     

基于单向无线网的飞行试验视频遥测传输技术

针对目前飞行试验视频遥测传输中遇到的遥测频带资源有限、传输视频路数少、数据保密性差等技术问题进行了分析,提出了采用单向无线网络进行数字视频遥测传输的技术优势,并对飞行试验单向无线网络数据传输中的网络通信协议进行了分析说明。提出采用H.264视频压缩技术进行飞行试验图像数据遥测传输的技术优势,针对在无线环境下视频传输需要解决的压缩数据编码问题,提出了采用分级编码技术和误码掩盖技术。结合飞行试验对研究结果进行了技术验证,并对试验方法和结果进行了说明。     

飞行试验遥测机载测试技术的发展与应用

随着现代飞机的先进性、复杂性和高度综合性的增强,在飞行试验测试中需要测量与记录的参数快速增长.在分析了国内外飞行试验遥测中机载数据采集系统现状之后,描述了我国飞行试验遥测面临的机遇与挑战,指出了飞行试验遥测系统网络化发展方向,最后提出了构建机载网络化采集记录系统的总体思路和研制的主要性能要求.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

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。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

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.     

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.     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。