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Imaging sensors are widely used in aerospace recently. In this paper, a vision-based approach for estimating the pose of cooperative space objects is proposed. We learn generative model for each space object based on homeomorphic manifold analysis. Conceptual manifold is used to represent pose variation of captured images of the object in visual space, and nonlinear functions mapping between conceptual manifold representation and visual inputs are learned. Given such learned model, we estimate the pose of a new image by minimizing a reconstruction error via a traversal procedure along the conceptual manifold. Experimental results on the simulated image dataset show that our approach is effective for 1D and 2D pose estimation. 相似文献
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航班量的快速增长使得各机场不能以本机场的效率最大为目标进行发展,而应该立足于整个机场群,探索在整个机场群效率最大化的条件下进行各机场持续发展的方法.基于此,选择DEA方法对我国三大机场群的效率进行分析,以机场群效率最大为目标,分析各输入指标对机场的敏感性;分别对三大机场群的效率进行评价,对非DEA有效的机场进行投影分析,指出其具体的改进方向;对三大机场群整体的效率进行比较分析. 相似文献
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A fast feature ranking algorithm for classification in the presence of high dimensionahty and small sample size is proposed. The basic idea is that the important features force the data points of the same class to maintain their intrinsic neighbor relations, whereas neighboring points of different classes are no longer to stick to one an- other. Applying this assumption, an optimization problem weighting each feature is derived. The algorithm does not involve the dense matrix eigen-decomposition which can be computationally expensive in time. Extensive exper- iments are conducted to validate the significance of selected features using the Yale, Extended YaleB and PIE data- sets. The thorough evaluation shows that, using one-nearest neighbor classifier, the recognition rates using 100-- 500 leading features selected by the algorithm distinctively outperform those with features selected by the baseline feature selection algorithms, while using support vector machine features selected by the algorithm show less prominent improvement. Moreover, the experiments demonstrate that the proposed algorithm is particularly effi- cient for multi-class face recognition problem. 相似文献
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Upset condition encountered by an aircraft in flight could pose great threat to flight safety, which is of chief importance in civil aviation. The causal factors have the nonlinear and multiple characteristics, and as a result the conventional envelope protection system cannot successfully do with the condition. So dynamic envelope based on differential manifold theory, which can take more coupling factors into account, is proposed as a basis to design a novel envelope protection system. Then the relationship between the dynamic envelope and the control coefficient or pilot command is obtained, and the result shows that the dynamic envelope can be enlarged with the change of control coefficient. Furthermore, quantification of flight security is realized via defining relative distance between flight state and dynamic envelope, which can detect whether there is a risk for an aircraft in flight. Finally, an envelope protection system based on dynamic envelope enlargement is proposed on the basis. NASA’s Generic Transport Model encountering hazard gust wind in climbing phase is taken as an example to verify the system’s feasibility. The result shows that the system can give a better operation encountering upset condition and to a certain extent reduce the number of accidents or incidents. 相似文献
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李龙顺 《中国民航学院学报》1993,11(3):51-55
本文简要介绍了放映氙灯电源的现状,详细研究了由中国民航学院三维显示技术研究所最新研制成功的放映氙灯电源中的稳流及稳纹波电路的设计思想和工作原理。理论分析和实验结果表明,本文设计的稳流及稳纹波电路显著地提高了氙灯电源的可靠性及减小了氙灯电流的纹波系数且操作简便,利于推广应用。 相似文献
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结合SY汇流板的结构和加工特点,采用优化加工参数、变更加工条件、改善刀具等方法控制和去除产品钻削加工过程中产生的毛刺。这几种方法经济适用,低成本高效率地应用于实际生产中。 相似文献
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一种新型便携式放映氙灯电源 总被引:1,自引:0,他引:1
李龙顺 《中国民航学院学报》1992,10(3):28-33
本文介绍了放映氙灯电源的构成、技术要求,详细研究了 KD750-C型放映电源的结构特点、工作原理及设计方法。理论分析和实验结果表明:按本文所述构成的 KD750-C 型放映电源是一种理想的氙灯工作电源。 相似文献