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《中国航空学报》2020,33(2):634-663
The determination of optimal aerial transport networks and their associated flight frequencies is crucial for the strategic planning of airlines, as well as for carrying out market research, to establish target markets, and for aircraft and crew rostering. In addition, optimum airplane types for the selected networks are crucial to improve revenue and to provide reduced operating costs. The present study proposes an innovative approach to determine the optimal aerial transport network simultaneously with the determination of the optimum fleet for that network, composed of three types of airplanes (network and vehicle integrated design). The network profit is maximized. The passenger’s demands between the airports are determined via a gravitational model. An embedded linear programming solution is responsible for obtaining potential optimal network configurations. The optimum fleet combination is determined from a database of candidate aircraft designs via genetic algorithm. A truly realistic airplane representation is made possible thanks to accurate surrogate models for engine and aerodynamics is adopted. An accurate engine deck encompassing a compression map and an innovative engine weight calculation besides an aerodynamical artificial neural network module enable a high degree of accuracy for the mission analysis. The proposed methodology is applied to obtain the optimum network comprised of twenty main Brazilian airports and corresponding fleet. 相似文献
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对无动力J—7LP动力学缩比模型进行了遥控试飞,以研究其失速尾旋特性,全偏平尾和方向舵可使模型进八尾旋,舵面全回中即可从各种尾旋中改出。偏转副翼对尾旋特性有明显的影响。 相似文献
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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. 相似文献
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研究了面向星敏感器的星模式识别算法。首先扼要介绍了到目前为止出现的所有面向星敏感器的星模式识别算法和星图预处理,然后详细论述了本文提出的基于旋转和比例不变点特征松弛匹配算法的一种新的面向星敏感器的星模式识别算法。在第三部分通过仿真试验检验了新算法的性能。初步的仿真试验结果表明该星模式识别算法性能优良,具有实用价值。最后讨论了待深入研究的问题。 相似文献
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To represent a stable environment despite the experience of changes during self movements, one can either develop an invariant allocentric representation, or update the egocentric representations as one moves. Using a disorientation paradigm, three sets of studies investigated these mechanisms in human navigation and scene recognition. Accuracy in the configuration of multiple object localization is impaired by disorientation, an effect not due to artifacts such as memory deterioration over time, intervening physical activities, uncertainty in self position and orientation, etc., suggesting one can locate objects primarily by updating their egocentric positions as she or he moves. Disorientation also impaired the judgment of changes to a scene after viewer movements, suggesting a similar egocentric updating process. On the contrary, representation of the shape of the surroundings is invariant and persists through disorientation. The coexistence of multiple mechanisms may increase the flexibility and robustness of the system. 相似文献
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应用联合变换相关器的成像制导系统 总被引:1,自引:0,他引:1
提出了一种光电混合的成像制导系统,它采用光学联合变换相关器作为其主要的图像识别单元,利用计算机对识别结果进行判决和显示,并发出跟踪信号给导引头,从而实现制导。联合变换相关器是对光学图像信号进行并行处理的器件,实时识别性能强,精度高。此成像制导系统克服了传统的红外制导系统易受外界因素影响,实时处理能力差,误判率较高的缺点,具有并行处理速度快、信息吞吐量大、体积小等优点,应用前景广阔。 相似文献
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