基于加速性能退化试验的IGBT故障预测前端设计

故障预测与健康管理(PHM)技术能够实现故障监测、诊断、预测、状态评估及综合决策的功能,能够降低飞行器维修、使用和保障费用,提高飞行器战备完好率、任务成功率以及安全性和可用性。针对航空电子单元故障预测具体实现这一问题,选择航空飞行器中常用的IGBT作为试验对象,采用加速性能退化技术,基于PXI的测控平台,研究IGBT故障预测试验加速性能退化试验技术,分析性能退化曲线,为IGBT加速寿命试验的实现奠定基础。     

可靠性工程技术应用讲座 第五讲：可靠性管理技术及应用

1可靠性管理的基本概念 可靠性管理就是从系统的观点出发,对产品全寿命周期中的各项可靠性工程技术活动进行规划、组织、协调、控制与怖督,以实现既定的可靠性目标,并保持寿命周期费用最省。因此,可靠性管理在所有可靠性活动中处于领导和核心地位。     

飞行器故障预测与健康管理(PHM)集成工程环境研究

故障预测与健康管理(PHM)技术能够实现故障监测、诊断、预测、状态评估及综合决策的功能,能够降低飞行器维修、使用和保障费用,提高飞行器战备完好率、任务成功率以及安全性和可用性;在分析了国内外研究现状的基础上,提出了构建飞行器故障预测与综合健康管理的通用化支撵平台和验证环境的设计思路,并展开描述了PHM开发环境、运行环境、验证环境的具体功能组成,研究成果能够为检验飞行器PHM系统工作效能提供有效验证,为降低飞行器PHM验证费用提供借鉴.     

重复使用运载器预测与健康管理(PHM)技术研究

为了实现传统一次性运载火箭的可重复使用特性,提高重复使用运载器的安全性、可靠性及维修保障性,破解重复使用运载器研制难度大、技术风险高的难题,研究了一种重复使用运载器的预测与健康管理系统方案;该系统采用一种“机载-地面”辅助决策的系统设计方案,机载部分采用分层分布式的系统架构设计方案,地面部分采用区域管理和综合调度的设计方案,有效实现运载器在线式健康状态监测与诊断;重复使用运载器预测与健康管理设计方案的应用,确保运载器在全寿命周期内,实现在线实时故障检测、故障预测和健康评估,为故障处理、维修保障和系统操作优化提供决策支持,显著提升了重复使用运载器的安全性、可靠性、保障性和效费比.     

一种综合飞行器健康管理模块的功能描述

飞行器的综合健康管理(IVHM)对于飞行器的安全性和可靠性十分重要.IVHM由几个子系统的健康管理系统的综合而成,能够完成故障诊断、失效预测、失效响应等功能,并且能够减少人为失误对飞行器的影响.     

飞行器网络化远程诊断防护系统

空间飞行器是集机械、液压、电子、热控等于一体的复杂大系统。由于飞行器结构部件繁多和工作环境多变，其安全性和可靠性一直是人们密切关注的研究热点。笔通过飞行器故障机理与人、机、环境的相关性研究，利用人工智能理论和方法，提出了基于虚拟仪器的飞行器网络化远程诊断防护方案，并对其实现技术进行了分析研究，为提高飞行器运行的安全性和可靠性提供了一种有效方法。     

基于复杂参数的组态化显示监控系统

随着我国航天飞行器发射频率的不断提高,以及各类预先研究型号的增多,对飞行器的测试效率提出了更高的要求。传统测发控软件由于型号需求差异,人员安排等问题,软件的设计与实现手段不同,一套软件通常只能针对一个型号,需求一旦变更,需要花费大量的人力财力开发与维护软件,同时也对保障软件的可靠性带来难度。为克服现有技术的不足,对组态化设计进行研究,采用了通用化接口设计及显示终端界面加载与数据显示方法关键技术,提出了一种基于复杂参数组态化显控系统,达到一套软件应用于多个型号的通用化目标,极大降低了控件灵活扩展与集成的难度,实现飞行器复杂参数测试数据的实时监控与软件的复用,大大提高了开发效率。     

面向寿命周期武器装备危险信息模型

安全性管理和安全性工程贯穿于武器装备型号寿命周期，期间需要大量信息支持，也会产生许多危险信息。该文提出面向寿命周期武器装备危险信息模型(HIMLC)，基于面向对象技术，对装备型号寿命周期中的危险信息进行集成，在PDM基础上，保证这些信息的完备性和一致性，为不同对象共享和有效管理危险信息提供基础。文章给出了模型的基本结构、三维视图及其形式化描述。     

系统健康管理中的寿命模型仿真研究

在航空、航天、通信等领域,高可靠性和长寿命设计的产品所占比重逐渐增大;性能退化状态评估和剩余使用寿命预测技术在提高该类产品安全性和维护效率、降低全寿命周期成本等方面意义重大;针对当前国内健康管理研究中缺乏寿命及可靠性基础数据的现状,介绍了系统寿命预测的典型过程,重点分析了寿命模型研究和仿真中存在的若干问题,旨在建立实现简单且与实际系统运行过程相似度高的寿命模型的建模方法,为后续系统性能状态评估提供有效的数据支持。     

飞行器远程故障诊断与健康监控

通过对飞行器故障机理与人、机、环境的相关性研究,利用人工智能理论和方法,提出了一种飞行器网络化远程故障诊断与健康监控方案,并对其实现技术进行了分析与研究,为提高飞行器运行的安全性和可靠性及对早期故障的适应与防护能力提供了一种新的技术途径.     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.