Digital Aircraft Sheet Metal Part Manufacturing System and Its Key Technology

The architecture of digital sheet metal manufacturing system is proposed based on the classification of sheet metal manufacturing information.The essence of digital manufacturing is the definition,management and transfer of information,and the key technologies are brought forward and described.It is pointed out that knowledge-based manufacturing elements design is necessary to make digital technology efficient.The management of all kinds of sheet metal manufacturing element information is to build single source of manufacturing data.Multi-state model-based digital transfer and coordination method is designed to provide a foundation for digital manufacturing of aircraft sheet metal part.The application of digital sheet metal manufacturing is exemplified with an aircraft sheet metal part.The application result is compared to that of the traditional analog transfer technology.It is shown that the developed technology can improve part quality,shorten manufacturing time and lower manufacturing cost.     

卫星成本预测的蒙特卡洛优化模型研究

传统的卫星成本预测模型预测结果单一，未考虑相应的不确定性因素。对此，提出了基于蒙特卡洛方法的卫星成本预测模型。该模型综合考虑了卫星成本技术的不确定性并给出了预测值的区间范围和概率分布。为了降低应用该模型所产生的误差，提出了最优分层抽样的方法，并通过划分分层区间提高了抽样的效率。最后，将收集到的相关数据代人该模型，其结果精度大约提高了10％左右。可见，使用优化的蒙特卡洛方法进行卫星成本预测具有较好的精确度。     

对国外机场起降费征收模式的经济学分析

介绍了国外机场起降费的3种主要征收模式.利用边际成本定价模式确定飞机所需交纳的起降费从经济学角度来说是富于效率的,并且相关的原则也为越来越多的机场所采纳.指出在中国航空运输业迅速发展的背景下,边际成本定价模式可以为改革现有机场起降时段分配机制提供一种指导思路.     

飞机概念设计中的生存力效益/代价综合评估方法

 首先介绍了军用飞机在常规武器威胁下的生存力评估指标及几种提高生存力措施；其次研究了将全因素试验法应用于评价生存力提高措施对生存力评估指标的增益影响的可行性；最后基于飞机的安全性、维修性、可靠性、保障性、性能及费用等约束条件，建立了一种能应用全因素试验法在飞机概念设计中进行飞机生存力效益／代价综合评估的方法。算例初步说明了方法的有效性。     

What do Cosmogenic Isotopes Tell us About Past Solar Forcing of Climate?

In paleoclimate studies, cosmogenic isotopes are frequently used as proxy indicators of past variations in solar irradiance on centennial and millennial timescales. These isotopes are spallation products of galactic cosmic rays (GCRs) impacting Earth's atmosphere, which are deposited and stored in terrestrial reservoirs such as ice sheets, ocean sediments and tree trunks. On timescales shorter than the variations in the geomagnetic field, they are modulated by the heliosphere and thus they are, strictly speaking, an index of heliospheric variability rather than one of solar variability. Strong evidence of climate variations associated with the production (as opposed to the deposition) of these isotopes is emerging. This raises a vital question: do cosmic rays have a direct influence on climate or are they a good proxy indicator for another factor that does (such as the total or spectral solar irradiance)? The former possibility raises further questions about the possible growth of air ions generated by cosmic rays into cloud condensation nuclei and/or the modulation of the global thunderstorm electric circuit. The latter possibility requires new understanding about the required relationship between the heliospheric magnetic fields that scatter cosmic rays and the photospheric magnetic fields which modulate solar irradiance.     

求解最小费用流的复合标号法

本文在求最短路和求最大流标号法的基础上,提出了求解最小费用流的复合标号法。利用这种方法可以在一次标号的过程中找到具有最小费用的增广链。该算法具有简单、易行、迭代次数少,而且易于理解的特点。     

Exploration and implementation of commonality valuation method in commercial aircraft family design

Commercial aircraft family design can reduce development costs, shorten development cycles, and expand the market coverage of aircraft. Commercial aircraft family development has become one of the most important features of modern aircraft design. This paper explores the effects of commonality on different aircraft models in a commercial aircraft family. The existing product commonality indexes are summarized and their limitations in the application to aircraft design are discussed. Then a new component commonality index is proposed based on the component decomposition structure. A model for calculating the aircraft program value is established,which considers development costs, manufacturing costs, sale price, operation costs and residual costs. The effects of aircraft commonality on time and economic costs of both development and manufacturing, and on sale price, are analyzed and quantified. The commonality evaluation strategy is obtained, which features comprehensive consideration of the aircraft program value and time costs. The break-even analysis of aircraft is proceeded on the basis of costs and price data. By using a real option method, the strategy considers the uncertainty of the aircraft program and the flexibility of the manufacturer. This strategy proves to be rational and applicable to aircraft design based on the calculation of three examples and the analysis of parameter sensitivity.     

飞机变形自动化测量方法研究

为解决以往飞机变形测量模式中人工干预较多,受测量环境影响较大,测量时间长等问题,基于Geo COM技术和RS232,在计算机与全站仪之间进行数据交换,设计了一套自动化测量系统。在测量过程中由标志点的机体理论坐标反算其在当前测站中的极坐标,从而在测量过程中驱动全站仪指向待测点,减少人工瞄准时间,并由计算机实时解算结果数据。经实际飞行试验验证表明,测量时间缩短为原来时间一半,大大提高了工作效率。     

旅游者出游激励理论探讨

从期望理论的视角审视旅游者的决策过程,主要借鉴维克托.弗鲁姆(Victor H. Vroom)期望理论的相关原理,初步搭建了旅游者出游激励理论的基本框架,解决了旅游者决策依据问题。通过旅游感知效价、旅游感知成本等全新概念的引入和一系列调查问卷的设计,最终得出了出游激励力的完整表达式并有以下阶段性结论:(1)信息准备是旅游感知效价、旅游期望值2、旅游感知成本的直接来源;(2)旅游感知效价、旅游期望值2、旅游感知成本对旅游者做出决策至关重要;(3)出游激励力是旅游者最终做出决策的惟一依据。     

浅谈水洗发动机对大修成本的影响

通过对深圳航空公司CFM56-7B发动机水洗方法改进前后的发动机进厂大修数据进行比较,主要分析HPT导向器报废率的变化,说明改进的发动机水洗方式对于延长发动机在翼时间、降低HPT导向器报废率、节约大修成本起到良好促进作用。