Software Design Techniques for Automatic Checkout

As electronic devices became increasingly more complex, it was no longer feasible to test such mechanisms with traditional methods. With practically no transition period, the need for a new technology came into existence. The amazing lack of an organized approach in the development of automatic testing techniques has been a handicap to much needed progress. This paper discusses some of the many problem areas that should be considered in the design of the software for a sophisticated checkout project.     

直升机批生产中的疲劳质量检验方法

本文论述了直升机关重件在批量生产中,疲劳质量控制所采用的抽检方法以及抽检原则。文中给出的大批量产品的抽样检验判断方法、小批量生产产品的抽样检验判断方法、最佳抽样检验法和改进的最佳抽样检验法均适用于直升机关重件的抽样检验。     

EIT Waves: A Changing Understanding over a Solar Cycle

We present here a review of observations and the current theories that attempt to explain coronal EIT waves. EIT waves were first observed by SOHO-EIT in 1996. Since then, careful analysis has shown that they are related to various other phenomena, such as: CMEs, coronal dimming regions, Moreton waves, and transverse coronal loop oscillations. Over the years, myriad theories have been proposed to explain EIT waves. Early attempts, while elegant, relied heavily on theories based on pre-coronal observations. More recent work, which tends to consider a larger data pool, has led to two competing theoretical camps: wave vs. non-wave models; in many cases, proposed hypotheses flatly contradict each other. Sifting through these seemingly-incongruous models requires a thorough understanding of the available data, as some observations make certain theories more difficult to justify. However, some questions still do not appear resolvable with current data and will likely require help from the next generation of coronal telescopes.     

Automatic Checkout and Monitoring in the AN TPQ-27 Radar System

This paper describes automatic monitoring equipment built in to a precision tracking radar system to detect and isolate faults. The purpose of the monitoring equipment is to minimize the mean time to repair faults and to exercise the overall system for pre-mission alignment and calibration. In addition, it is used to periodically check for performance degradation in key areas of the system. The paper describes the design approach used to meet the above requirements. Three types of signals are monitored: analog, digital, and switch closure. A list of each type is given and the technique used to monitor each is described. The design approach for pre-mission alignment and calibration is outlined. Tests performed are: RF alignment of the boresight axis, range tracking accuracy, angle servo calibration and accuracy, and receiver figure of merit measurements.     

测试系统检查仪频率信号发生电路设计

根据某飞机机械检测车试车测试系统检查仪研制任务的需求,分析了航空发动机转速频率信号和振动频率信号,设计了模拟相应频率信号的发生电路,并实际应用于检查仪的研制。     

非常规的思维--美国边疆航空公司改变维修策略的故事

航空公司维修策略的传统思维是：如果你经营一家小的、新运营的航空公司，你必须在公司外部为飞机的深度检修寻找一个维修厂家。而边疆航空公司却反其道而行之，采用了自行维修方式，不仅降低了成本，还提高了效率。特别是作为一家小航空公司，确保了它的正常运营     

Changing safety-critical software

Changing software to implement new features, correct problems, update functions, or replace obsolete hardware components (e.g., microprocessors) is a way of life in today's industry. A systematic software change process is essential for the maintenance and reuse of safety-critical software. This paper presents activities to consider when changing software in safety-critical systems. The focus is on the aviation industry; however, the concepts are also applicable to other safety-critical domains, such as medical or nuclear     

改变游戏规则的技术创新——普惠PurePowerTM PW1000G型发动机

世界主要航空发动机制造商都在积极探索如何提升发动机的性能,普惠航空发动机公司的成功答案是:PurePowerTM PW1000G--洁静动力TM PW1000G型发动机.     

入世:法律环境的变化与中国民航行政管理的对策研究

从入世前后中国民航行政管理的法律环境发生的巨大变化入手,探讨了中国现行民航行政管理体制可能遭遇的机遇和挑战;依据现代行政管理理论的新发展,为中国民航的行政管理改革提出了一些政策建议。     

飞机驾驶舱的开关正在发生变化

飞机驾驶舱内的开关众多,它们是驾驶员改变飞机状态的基本控制装置,也算得上是驾驶舱的人机接口之一。目前机电式的开关仍然是驾驶舱的主体,但由于重量轻、成本低的固态开关的出现,这种局面未来将发生改变。开关的对操控飞机的重要性不言而喻,其可靠性、可达性和使用方便是其最基本的要求。传统的机电式开关具有承载大电流的能力,同时飞行员在按压或旋转时它们时会有一种反馈的触感。而固态开关由     

日新月异的驾驶舱显示器

在民用电子产品的快速升级和新型飞机相关技术进步的推动下,驾驶舱显示技术不断发展。显示器尺寸的日益增大,产品可靠性和成本问题已受到业内关注;未来驾驶舱仪表板很有可能从左到右只设一个显示器;飞行显示器制造商正在借鉴有关民用技术,发展触摸屏幕显示器和有机发光二极管显示器。     

航空维修业的角色转换

在快速变化和充满挑战的环境中,航空公司、制造商(OEM)和服务供应商(MRO)都在不断地变换自己的角色,力争成为市场的赢家.     

航空维修业的角色转换

在快速变化和充满挑战的环境中,航空公司、制造商(OEM)和服务供应商(MRO)都在不断地变换自己的角色,力争成为市场的赢家。     

高油价下的航空运输业遭遇困境

进入2008年以来,国际油价在震荡中不断走高,到7月初已达到140美元以上,较年初的110美元涨幅近30％。与此同时,发达国家的经济受美元贬值和次贷危机等因素影响,航空乘客数量减少,这两项累加给一些刚刚开始盈利的航空公司带来了沉重打击。为此,国际民航组织已经调低了2008年对其成员航空公司的行业利润预期。     

浅析后勤社会化后会计核算的转变

随着高校后勤社会化改革的深入 ,后勤从学校逐渐剥离出来 ,变行政拨款制为服务收费制 ,即学校取消对后勤的行政拨款 ,将原下拨给后勤的经费直接拨付校内各用户单位 ,后勤需通过向各用户单位提供服务并计价收费来实现自主经营、自负盈亏 ,从而形成市场经济条件下完全的企业化管理。后勤财务为适应后勤企业化管理的需要 ,应由事业型财务向企业型财务转变 ,由遵守《事业单位会计准则》向遵守《企业会计准则》转变 ,对于具体的转变及调整我认为主要有以下几点。　　一、会计核算由收付实现制转为权责发生制事业单位会计核算一般采用收付实现制 ,…     

MRO供应链软件概述

基于性能的后勤保障(PBL)和精益维修(Lean MRO)等新的维修模式和经营策略的发展给航空维修(MRO)业带来了重大变化,使MRO业与汽车制造和制药等行业一样,可以通过供应链技术协调各供应商,进行部件的跟踪和记录保存.     

焊接导管轨迹焊新工艺

本文阐述了航空发动机导管的焊接新工艺——轨迹焊及其特点、所用的设备、工艺参数、工艺要点、以及焊接过程中易于出现的缺陷和排除方法。     

农民画:当代中国的时代映像

在中国生活哪怕只是来旅行的人,对农民画都不会陌生。城市的街头巷尾、建筑工地的防护墙上,报纸电视网站的广告里,到处都是这种色彩鲜艳的民俗风情画,配有各种应景的口号和宣传标语,绝对是中国一景。事实上,自从中国文化部在1988年命名了35个农民画创作突出的县乡为中国现代民间绘画画乡之后,很多省市县将其所在地的农民画认定为非物质文化遗产。     

动态MBean的原理及其对可变资源进行管理的应用

根据JMX框架管理应用程序的基本原理,分析了现实中可管理资源大多会随时间而发展变化的情况,针对可变资源给管理工作带来的困难,深入研究了JMX规范中定义的动态MBean,结合其它有关的java技术,给出了相应的解决方案。     

The Changing Face of Titan’s Haze: Is it all Dynamics?

Titan’ atmosphere shows some similarities with that of the Earth, in terms of composition and surface pressure. Also, its seasonal cycle is similar, as Titan’ obliquity is about 27^°(23^°,5 for the Earth), although it is about 30 times as long. Titan’ haze exhibits an albedo contrast (NSA for North-South Asymmetry) that is changing seasonally. From the analysis of Voyager and Hubble Space Telescope data, we learned that at short visible wavelengths, the albedo of the winter hemisphere is lower by 10-20% than that of the summer hemisphere. This asymmetry peaks at 450 nm and reaches maximum amplitude around Titan’ equinoxes. It reverses in about five years, faster than a season which spans seven years. At longer wavelengths, longward of 700 nm, the asymmetry is inverted. The NSA reversal process in the red and in the UV seems to lead the reversal in the blue by 1 or 2 years. No valid explanation exists for this lag, at least in the red. The results from a recent model which couples atmospheric dynamics, haze microphysics and transport, as well as photochemistry, show that the NSA and its seasonal changes can be explained by an accumulation of haze particles at the winter pole. This is due to the pole-to-pole Hadley circulation pattern that is present during most of Titan’ year and rapidly disrupts at the time of the equinoxes. This model can also explain the observed cooler stratospheric temperatures and higher abundances of heavy hydrocarbons and nitriles in the winter polar region. In addition, it provides a mechanism for the formation of a detached haze layer around 300–400 km altitude, as well as the existence of a polar hood. Thus, it appears that the latitudinal contrasts we observe on Titan are conveniently tracing for us the dynamical behavior of its atmosphere.