Microprocessor smart cards with fingerprint user authentication

Due to the great increase in Information Technology (IT) systems where user authentication is needed, security in those systems relies on using PINs or passwords. During recent years, the scientific community has been trying to improve biometric techniques to be accepted as an alternative to other user authentication schemes. One of the sectors where user identity must be verified, is the identification cards sector. In fact, if great security wants to be achieved, smart cards should be used. But cardholder verification is performed using Card Holder Verification Keys (CHV-Keys), which are PIN-based. The authors are trying to integrate fingerprint verification inside a smart card, following their works in the past. The fingerprint scheme used is shown, and the work to achieve the integration inside a commercial smart card is detailed.     

不同尾翼灵巧子弹气动特性实验研究

从无伞灵巧子弹稳态扫描的必要条件出发,设计了轴向折叠和径向折叠两种尾翼类型的子弹气动外形。设计了模型和实验装置,进行了小迎角低速风洞实验。获得了模型在固定和旋转条件下的气动力数据,测量了模型在气动力作用下的转速,对模型的稳定性进行了分析。实验结果表明：模型采用轴向折叠尾翼,能够设计足够有效的迎风面积和增阻效果良好的翼面形状,维持较为稳定的转速,具有良好的旋转稳定性;采用径向折叠尾翼的模型,增阻效果不明显,稳定旋转能力较差。实验结果为无伞灵巧子弹的设计提供了重要参考。     

Application of GTE cycle with heat supply at constant volume

The experimental and theoretical studies of a GTE cycle with heat supply at constant volume were carried out. The results presented were obtained with the use of a constant volume valve combustion chamber of a new type with a turbine, low-head ejector in front of the turbine and a rotary-piston expansion machine as a turbine. Possible variants of gas-turbine plant (GTP) design with a low-head ejector and rotary-piston expansion machine are shown.     

Optimization of dynamic performance for a ground catapult with reusable supply of the working fluid

A task of minimizing the guide length of a ground catapult was set in order to ensure the mobility for unmanned aircraft systems. A scheme with reusable supply of the working fluid into the pneumatic drive cylinder was proposed. A method of parametric optimization of dynamic performance for a catapult was formulated. The method and models were verified with respect to the basic integral indicators.     

脉冲风洞发动机试验多油位多时序高精度燃料供应系统

针对脉冲风洞超燃冲压发动机试验要求燃料供应快速、稳定、精确的特点,设计了一套燃料供应系统,可多油位多时序高精度地实现试验模型燃料供应、模型点火器气源供应、气体节流气源供应等功能。该系统供应的燃料为乙烯、甲烷、氢气及其混合物。采用压力补偿装置,保持燃料稳定供应,实现燃料当量比精确控制。设计了由电磁阀和气动阀组合而成的快速供气阀门,阀门开启时间小于20ms,关闭时间小于30ms,实现燃料的安全、快速供应。对超燃发动机模型不同油位设计了专门的供油回路,通过电磁阀控制系统,实现多个油位不同时序的控制动作,时序控制精度达到1ms。给出了详细的系统设计回路,并对关键部件参数进行了计算。点火试验表明该系统可以为点火器提供稳定的空气和氢气,点火器正常时间超过500ms。在脉冲式直连式试验台上,进行了乙烯燃料超燃发动机试验,对该套供油系统进行了测试。试验监控了供油管道及模型壁面的压力分布,供油压力在试验时间内波动小于3%,发动机壁面压力显示燃烧性能良好。空气节流试验表明,该系统提供的时长为100ms、压力为4.7MPa的节流空气成功点燃了乙烯。     

The design of a nuclear power supply with a 50 year lifeexpectancy: the JPL Voyager's SiGe MHW RTG

Between 25 and 30 years ago, the IECEC Proceedings carried a series of papers by the present authors and other members of a JPL team on the problems and the desirable design features associated with the MHW RTGs to be used to power JPL's Voyager I and II spacecraft. The Voyager I and II spacecraft successfully completed their original 12 year missions 10 years ago and are at distances of over 55 AU and 70 AU from the sun. The power systems worked almost precisely as predicted. The Voyager spacecraft seem to have several decades of life left to make measurements outside the solar system. This paper gives a technical overview of the design process and problems     

如何看待中美航权的进一步开放

自2004年《中美航空运输协定》签署以来,中美航权问题一直是业内争论的热点话题,而前不久在第二次中美战略经济对话期间,中美航空运输当局签署的新航权协议,又一次引起广泛关注。新协议规定,在2007～2012年的5年内,中美双方在美国至中国东部地区的客运运力将逐步增加到70班/周,这相当于到2012年,每天从美国飞往中国的航班数量在今年的基础上将增加一倍,即美国的航空公司往返中美两国间的每日航班数将由目前的10班增至23班。同时,我国中部地区(安徽、湖南、湖北、江西、河南、山西)至美国的直达航空运输市场将完全开放。中国的航空公司也可以不受限制地进入这一市场。     

高固体漆的应用

根据环保要求,航空用油漆正在逐渐由传统型转变成环保型。本文介绍了高固体漆在飞机上应用的现状以及存在的问题。     

借鉴国外解决航班延误的办法

世界范围内的航空公司均有航班延误现象发生,导致延误的影响因素较多,但国内现有解决航班延误问题的方法似乎较少,官方文件仅有民航总局公布的《航班延误经济补偿指导意见》,而国外一些国家针对航班延误问题的解决方式,或许对解决我国民航航班延误问题能够有所借鉴     

利用FMS提高运行效益的方法

中国民航现有的大型客机绝大多数都装备有飞行管理系统(FMS),虽然它具有性能管理、自动飞行、区域导航等功能,但是,由于航路结构、管制的限制以及应用不利等种种原因,FMS没有充分发挥作用并带来应有的效益。本文结合我国情况,从改变飞行计划、调整成本指数、飞机调速.选择爬升/下降剖面、调整飞行高度层等方面,提出了降低运行成本,提高运行效益的方法。     

当前民航业的挑战与对策2009中国民航发展论坛侧记

当前,全球性的经济衰退导致民航业市场需求显著减缓,使得民航业遭遇空前困境。业界已经意识到。整个民航业是一个利益攸关摗要,需要共同面对危机、迎接挑战。在5月14日召开的“2009中国民航发展论坛”上,来自政府,国际民航组织、航空运输企业,大学等30余位领导和专家,     

构造含结点旋转单元的坐标变换法

Ａｌｌｍａｎ提出了带角结点旋转的三角形单元及相应的四边形单元，法向位移的二次插值保证了该单元的精度，但带来了构成单元的复杂。本文把Ａｌｌｍａｎ单元看成是对一个有边中结点单元进行坐标变换的结果，大大提高了计算效率。     

GPS navigation with increased immunity to modeling errors

A robust extended Kalman filter (EKF) is presented for GPS navigation with outlying errors in the GPS measurements due to failed satellites or unmodeled errors. In this approach, the innovation step of the conventional EKF is modified using the robust statistics concept to obtain a more accurate state estimate in the presence of outlying errors. Performance of the proposed robust EKF in comparison with the conventional EKF, and adaptive EKF is demonstrated through simulation results.     

Minimum Sensitivity Controllers with Application to VTOL Aircraft

A technique is described for the design of a fixed-gain feedback controlier for a vertical takeoff and landing (VTOL) aircraft, which minimizes the effect of arbitrary variations in the aircraft dynamics on aircraft performance over varying flight conditions. The design method involves the assignment of the eigenvalues of the aircraft model to prescribed locations in the complex plane and the minimization of their sensitivities to model parameter variations. This controller is shown to possess better tracking and regulating capabilities than another fixed-gain controller designed merely for assignment of eigenvalues using nominal parameter values, without any consideration of their sensitivity to plant parameter variations.     

空客考虑和巴西合作下一代A320

空客公司为了应对波音研制新一代波音737的挑战,决定研制新一代 A320,并希望和巴西航空工业公司合作。     

用DEA方法评价先进制造技术的新方法

简要回顾ＤＥＡ（Ｄａｔａ Ｅｎｖｅｌｏｐｍｅｎｔ Ａｎａｌｙｓｉｓ）方法在ＡＴＭ（Ａｄｖａｎｃｅｄ Ｍａｎｕｆａｃｔｕｒｉｎｇ Ｔｅｃｈｎｏｌｏｇｙ）评价中的研究现状,分析了ＤＥＡ方法及其改进形式所存在的问题,并提出了解决这些问题的一种新方法。