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61.
Helicopters are playing an increasingly important part in emergency relief, such as earthquake rescue, firefighting and medical transport. With the development of virtual simulation technology, virtual simulation-based training is widely used in the training of the helicopter crew especially for the dangerous and costly missions mentioned above. A complete training effectiveness evaluation method is proposed to evaluate the trainees’ training effect based on virtual simulation in this paper. A key to this method is regarding the complicated process as a discrete event-activity flow system and establishing the evaluation indicator system. Then expert group and Analytical Network Process (ANP) are applied to determine the weight of indicators. When the training data are processed, there is a novel attempt to apply Fuzzy Comprehensive Evaluation (FCE) model to calculate the two categories of indicators. Eventually, an experiment and the analysis were carried out to validate the evaluation method. 相似文献
62.
针对航天控制产品精密复杂零件的工艺难点,以该类零件的工艺设计过程为主线,分别论述了材料定额编制、工艺路线设计以及工序设计过程中的注意事项和工艺方案设计方法,并以实例进行了简要说明。 相似文献
63.
The proposed space experiments BOSS (Biofilm Organisms Surfing Space) and BIOMEX (BIOlogy and Mars experiment) will take place on the space exposure facility EXPOSE-R2 on the International Space Station (ISS), which is set to be launched in 2014. In BOSS the hypothesis to be tested is that microorganisms grown as biofilms, hence embedded in self-produced extracellular polymeric substances, are more tolerant to space and Martian conditions compared to their planktonic counterparts. Various microbial biofilms have been developed including those obtained from the cyanobacterium Chroococcidiopsis isolated from hot and cold deserts. The prime objective of BIOMEX is to evaluate to what extent biomolecules are resistant to, and can maintain their stability under, space and Mars-like conditions; therefore a variety of pigments and cell components are under investigation to establish a biosignature data base; e.g. a Raman spectral library to be used for extraterrestrial life biosignatures. The secondary objective of BIOMEX is to investigate the endurance of extremophiles, focusing on their interactions with Lunar and Martian mineral analogues. Ground-based studies are currently being carried out in the framework of EVTs (Experiment Verification Tests) by exposing selected organisms to space and Martian simulations. Results on a desert strain of Chroococcidiopsis obtained from the first set of EVT, e.g. space vacuum, Mars atmosphere, UVC radiation, temperature cycles and extremes, suggested that dried biofilms exhibited an enhanced survival compared to planktonic lifestyle. Moreover the protection provided by a Martian mineral analogue (S-MRS) to the sub-cellular integrities of Chroococcidiopsis against UVC radiation supports the endurance of this cyanobacterium under extraterrestrial conditions and its relevance in the development of life detection strategies. 相似文献
64.
《Aerospace Science and Technology》2007,11(7-8):507-517
The present numerical study was performed to investigate the impact of both the Reynolds number variation and the used turbulence model to capture the boundary layer development on the characteristic of a BR710 fan blade. A one-equation model of Spalart Allmaras with an optional semi-empirical transition model of Abu-Ghanam Shaw has been applied. The transition model allows the boundary layer development from a laminar to a turbulent behaviour to be taken into account. This is of particular importance at low Reynolds numbers and thus high operating altitudes of airplanes when the transition location moves further downstream to the trailing edge. Therefore the interaction between the shock waves of the transonic fan blade row and the boundary layer leads to a significant change of the characteristic. The steady numerical studies of the 3-D blade passage have been carried out with the commercial 3-D Navier–Stokes solver NUMECA. Additionally an unsteady calculation has been applied to explain the penalty in efficiency on high operating altitudes. 相似文献
65.
This paper explores how the WTO process may affect the development of commercial space industries in Asia. It does so by examining how the ever greater reach of trade rules may constrain industrial and technology policies aimed at developing an indigenous space capability. The role of the USA is also examined, as it is the US industry that will be among the most affected by increased competition in satellite and launcher services. 相似文献
66.
This paper describes one solution to the problem of providing Perimeter Intruder Detection, (PIDS), for sites whose boundary includes direct access from uncontrolled water. Two surveillance heads were proposed, each consisting of a TI camera and a Colour CCTV camera mounted on a pan and tilt unit 相似文献
67.
介绍烟箱重量在线检测系统的主要研究内容,概括硬件的结构以及选用的主要设备,阐述上位机软件的主要模块及实现方法。 相似文献
68.
The High Reynolds Number Aero-Structural Dynamics (HIRENASD) project is conducted by the Collaborative Research Center “Flow Modulation and Fluid-Structure Interaction at Airplane Wings (SFB 401)” at RWTH Aachen University. It is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG) since 2004. Steady and unsteady state experiments with an elastic semispan wing model were performed under transonic and high Reynolds number conditions in the European Transonic Windtunnel (ETW) in Cologne, Germany. The main components of the complete windtunnel assembly were the wing model itself, a piezoelectric 6-components balance and a mechanical excitation mechanism able to excite the wing model at selected resonance frequencies. These components were designed, sized and assembled at the Department of Aerospace and Lightweight Structures at RWTH Aachen University. The dynamic qualification of the windtunnel assembly under wind-off condition was carried out in the department's test laboratory. Modal survey testing based on the hammer impact method was performed, as well as response decomposition analysis using enforced excitation by means of the mechanical excitation mechanism itself. Within the qualification, a test procedure enabling investigations of modal parameter changes under wind-off and wind-on conditions in a cryogenic windtunnel was also verified. 相似文献
69.
目前,基于快速建模下的重量重心估算系统得到了快速发展。为了进一步提高结构重量估算精度,研究了如何在重量重心快速分析(WCGA)系统环境中构建优化模块。以机翼结构重量优化为例,提出优化流程,对优化模块功能进行分解,给出模型简化要求。以A320飞机机翼为例,对梁和长桁进行优化,结果显示,经过优化,有效减轻了结构重量,且相比于传统的减重优化设计方法,极大提高了计算效率。 相似文献
70.
探月工程对飞行器导航系统的性能提出了更高要求,因而有必要研究GNSS(Global Navigation Satellite System,全球导航卫星系统)接收机在探月任务中的应用。以探月工程三期为应用需求,开展地-月-地转移过程中的GNSS接收机可用性分析、GNSS信号特性分析;并针对低信噪比环境下的高灵敏度接收机系统应用进行设计,采用弱信号捕获算法和弱信号跟踪算法实现-175dBW的灵敏度;最终采用基于轨道动力学模型的卡尔曼滤波方法实现了GNSS自主定轨算法。仿真表明:GNSS接收机在60 000km以下的地-月转移和月-地转移弧段能够为探月飞行器提供100m以内位置精度的导航服务。 相似文献