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2篇 您的检索式:作者名="Xiangcong Zhou"
    题名 作者 年代 出处 被引量
1A ubiquitous knowledgeable data representation model(UKRM) for three-dimensional geographic information systems(3D GIS)显示文摘In the face of complicated, diversified three-dimensional world, the existing 3D GIS data models suffer from certain issues such as data incompatibility, insufficiency in data representation and representation types, among others. It is often hard to meet the requirements of multiple application purposes(users) related to GIS spatial data management and data query and analysis, especially in the case of massive spatial objects. In this study, according to the habits of human thinking and recognition, discrete expressions(such as discrete curved surface(DCS), and discrete body(DB)) were integrated and two novel representation types(including function structure and mapping structure) were put forward. A flexible and extensible ubiquitous knowledgeable data representation model(UKRM) was then constructed, in which structurally heterogeneous multiple expressions(including boundary representation(B-rep), constructive solid geometry(CSG), functional/parameter representation, etc.) were normalized. GIS's ability in representing the massive, complicated and diversified 3D world was thus greatly enhanced. In addition, data reuse was realized, and the bridge linking static GIS to dynamic GIS was built up. Primary experimental results illustrated that UKRM was overwhelmingly superior to the current data models(e.g. IFC, City GML) in describing both regular and irregular spatial objects.ZHANG ShuQing ZHOU ChengHu ZHANG JunYan CHEN XiangCong 2016Science China Earth Sciences2016,59,4:2
2Liftoff of a New Hovering Oscillating-wing Micro Aerial Vehicle显示文摘Hovering ability forms the basis for space operations of Micro Aerial Vehicles(MAVs).The problem of uneven load puts high demands on the wing design.In this paper,a new hovering-mode for MAVs,inspired by flapping flight in bees and hummingbirds but using high-aspect-ratio and low-stress wings,is proposed.Different from the flapping actuations that occur at the wing roots,the two wings are driven back and forth in a straight line.To simplify the design and control the angle of attack,passive wing rotation is employed.The numerical results and analysis show that the maximum stress of the oscillating wing is approximately 1/6 of that of the flapping wing when the lift of the oscillating wing is twice that of the flapping wing.A theoretical aerodynamic model of the kinematics of the vehicle's driving mechanism was developed to fulfill its design.Force measurements indicate that the vehicle generates a sufficiently high cycle-averaged vertical thrust(71 g)for liftoff at a maximum frequency of 5.56 Hz,thereby validating the proposed aerodynamic model.Moreover,liftoff performance is presented to visually demonstrate the vertical take-off capabilities and hovering potential of the aeromechanical solution.Xiangcong Zhou Deyuan Zhang Zhiyong Huang Xiaogang Song Hao Liu Lin Feng 2021Journal of Bionic Engineering2021,18,3:0
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