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191.
新型充气展开遮光罩设计方案研究和仿真分析 总被引:2,自引:0,他引:2
设计一种充气展开遮光罩结构,实现径向和轴向依次展开.提出遮光罩的结构方案、折叠方式和结构中各组件合适的材料,使得结构展开状态和折叠状态分别能够达到一定的尺寸要求.文章还对充气展开遮光罩进行静力分析和展开过程仿真,仿真分析结果表明,遮光罩能够顺利展开,遮光罩壁保持理想的工作表面. 相似文献
192.
The woven fabric membrane materials are widely used in space and terrestrial inflatable reflectors. However the material?s anisotropy makes the design analysis more complex. The deviation from the desired shape, so-called “W-profile error”, influences the precision of the membrane surface significantly. In this study, a model of an axisymmetric paraboloid surface using membrane theory is established for the purpose of facilitating the surface precision optimization. Analytical solutions for displacements of the reflector are derived. An iteration method of initial reflector profile solution is stated and a finite element (FE) software employed in the solution is presented. A case study is illustrated to make a comparison between numerical and theoretical analyses. Finally, the conclusions are drawn that the analytical method and the FE iterative method for initial profile solution are feasible and efficient. 相似文献
193.
飞机油量传感器布局设计的CAD方法的研究 总被引:1,自引:0,他引:1
根据飞机燃油油量测量的原理引出了数字式燃油测量系统中油量传感器的布局原则,由此提出了可测区的概念,并对相应的可测区计算方法中的关键技术作了阐述。最后给出了通过可测区计算及可测性验证进行油箱中油量传感器布局设计的有关结论。 相似文献
194.
社会经济系统的运行规律同生态系统之间存在着极强的相似性和关联性.运用生态学方法解析企业集团生态位现象,并结合系统论和突变论的思想,提出了企业集团生态住因子维度体系,构建了中国电子企业集团生态位突变模型,既为企业仿生研究提供了一个新的研究视角,也可对企业战略管理具有一定的指导作用. 相似文献
195.
The continuous growth of air traffic has led to acute airspace congestion and severe delays, which threatens operation safety and cause enormous economic loss. Flight assignment is an economical and effective strategic plan to reduce the flight delay and airspace congestion by reasonably regulating the air traffic flow of China. However, it is a large-scale combinatorial optimization problem which is difficult to solve. In order to improve the quality of solutions, an effective multi-objective parallel evolution algorithm(MPEA) framework with dynamic migration interval strategy is presented in this work. Firstly, multiple evolution populations are constructed to solve the problem simultaneously to enhance the optimization capability. Then a new strategy is proposed to dynamically change the migration interval among different evolution populations to improve the efficiency of the cooperation of populations. Finally, the cooperative co-evolution(CC) algorithm combined with non-dominated sorting genetic algorithm II(NSGA-II) is introduced for each population. Empirical studies using the real air traffic data of the Chinese air route network and daily flight plans show that our method outperforms the existing approaches, multiobjective genetic algorithm(MOGA), multi-objective evolutionary algorithm based on decomposition(MOEA/D), CC-based multi-objective algorithm(CCMA) as well as other two MPEAs with different migration interval strategies. 相似文献
196.
Measuring air traffic complexity based on small samples 总被引:1,自引:0,他引:1
Air traffic complexity is an objective metric for evaluating the operational condition of the airspace.It has several applications,such as airspace design and traffic flow management.Therefore,identifying a reliable method to accurately measure traffic complexity is important.Considering that many factors correlate with traffic complexity in complicated nonlinear ways,researchers have proposed several complexity evaluation methods based on machine learning models which were trained with large samples.However,the high cost of sample collection usually results in limited training set.In this paper,an ensemble learning model is proposed for measuring air traffic complexity within a sector based on small samples.To exploit the classification information within each factor,multiple diverse factor subsets (FSSs) are generated under guidance from factor noise and independence analysis.Then,a base complexity evaluator is built corresponding to each FSS.The final complexity evaluation result is obtained by integrating all results from the base evaluators.Experimental studies using real-world air traffic operation data demonstrate the advantages of our model for small-sample-based traffic complexity evaluation over other stateof-the-art methods. 相似文献
197.
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199.
Due to rapid development in the past decade, air transportation system has attracted considerable research attention from diverse communities. While most of the previous studies focused on airline networks, here we systematically explore the robustness of the Chinese air route network, and identify the vital edges which form the backbone of Chinese air transportation system. Specifically, we employ a memetic algorithm to minimize the network robustness after removing certain edges, and hence the solution of this model is the set of vital edges. Counterintuitively, our results show that the most vital edges are not necessarily the edges of the highest topological importance, for which we provide an extensive explanation from the microscope view. Our findings also offer new insights to understanding and optimizing other real-world network systems. 相似文献
200.