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151.
This paper aims to qualify the behaviour of contributors to OpenStreetMap (OSM), a volunteered geographic information (VGI) project, through a multigraph approach. The main purpose is to reproduce contributor’s interactions in a more comprehensive way. First, we define a multigraph that combines existing spatial collaboration networks from the literature with new graphs that illustrate collaboration based on specific aspects of the VGI modes of contribution through semantics, geometry and topology. Indeed, the ways that contributors interact with one another through editing, completion, or even consumption may provide additional information on each user’s operation mode and therefore, on the quality of the contributed data. Social collaborations drawn from indirect criteria – for example, comparisons between contributors’ activity areas – can also be contemplated under another network. Second, the resulting multigraph is analysed using data mining approaches to characterise individuals and identify behavioural groups. The implementation of a multiplex network based on an OSM data sample and an initial analysis make it possible to identify useful behaviours for data qualification. The initial results characterise some contributors as pioneers, moderators and truthful contributors, according to their special roles in the graphs. Mapping elements that include these contributors’ participation are likely to be reliable data  相似文献   
152.
Conservation Development (CD) is a land-use tool to reduce the impacts of development on natural resources, yetthe use of CD is highly variable. We used a collaborative conservation model to examine factors influencing adoption and implementation to improve the future application of CD. We interviewed 2–3 individuals including planners, board members, and developers (n?=?46) from 16 rural communities in the intermountain west and northeast U.S. Motivations to preserve rural character or comply with state statutes drove adoption. Greater capacity such as outside expertise, model regulations, and iterative revisions of ordinances was associated with stronger ordinances. Adoption processes including ample dialog across diverse constituents, especially those overseeing subdivision development, facilitated higher rates of implementation. Concerns over open space management, lack of successful CD examples, and inexperience with CD posed barriers to implementation. Understanding social context revealed the strengths and shortcomings of CD and provided guidance for strategically engaging communities in private lands conservation.  相似文献   
153.
154.
In the past studies on pile vibrations, the soil around the pile is mainly regarded as homogeneous or multi‐layered piecewise homogeneous. However, under most engineering conditions, the surrounding soil becomes seriously disturbed due to construction effects. This may strengthen or weaken the shear modulus of the soil resulting in the soil becoming radially inhomogeneous. As a consequence of this, El Naggar extended Novak's plane‐strain model to account for the radial inhomogeneity by the use of multiple springs connected in series. Rather than using this approach, this paper proposes a new model which is thought to be theoretically more rigorous and one which may be described as complex stiffness transfer model. It is shown that the solution developed in this study agrees well with the more limited solutions of Novak and Dotson and Veletsos under several special conditions. Finally, the scope of application has been enlarged as a result of the generalizations made in the present model. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
155.
This paper presents the analytical layer‐element method to analyze the consolidation of saturated multi‐layered soils caused by a point sink by considering the anisotropy of permeability. Starting from the governing equations of the problem, the solutions of displacements and stresses for a single soil layer are obtained in the Laplace–Hankel transformed domain. Then, the analytical layer‐element method is utilized to further derive the solutions for the saturated multi‐layered soils in the transformed domain by combining with the boundary conditions of the soil system and continuity conditions between adjacent layers. The actual solutions in the physical domain can be acquired by the inversion of Laplace–Hankel transform. Numerical results are carried out to show the accuracy and stability of the proposed method and evaluate the influence of sink depth and anisotropic permeability on excess pore pressure and surface settlement. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
156.
信息技术的快速发展使身份认证机制的安全性得到越来越广泛的关注.但现有的身份认证机制存在着隐私泄露等风险,这就要求设计出更加可靠的身份认证机制.本文利用区块链的去中心化、不可篡改等特性,设计出基于区块链的多方协作安全身份认证机制.在实现可靠身份认证的同时,保证信息的权威性,在一定程度上减少数据冗余,并提高身份认证效率,保证全面且准确的身份认证.最后实现支持多个数据服务商对身份信息进行加密签名,保护数据隐私,以及多方共享数据的身份认证系统.  相似文献   
157.
针对农用拖拉机智能化程度低,以及现有的人工智能水平尚无法完全实现自主驾驶控制拖拉机等问题,本文设计一种基于人机协作的拖拉机驾驶机器人.拖拉机驾驶机器人可以对拖拉机进行快速、无损、智能化升级,其结构由转向控制机械手、换挡机械手、旋耕机升降控制机械手和踏板控制机械腿等组成.通过研究人机协作的控制方法,提出了人机协作介入准则和基于转向电机电流反馈扭矩检测的人机协作模式切换方法,研制了原理样机验证拖拉机驾驶机器人的可行性和人机协作控制策略的有效性,对促进精准农业,提高现代农业智能化装备水平具有重要的现实意义.  相似文献   
158.
针对建筑物精细建模的精度问题,对同一试验区建筑物群的机载LiDAR顶面数据、航空正射影像数据和车载LiDAR立面数据进行试验研究,通过精确提取各建筑物群的顶面和底面矢量轮廓线,对矢量轮廓线间的水平间距进行定性与定量分析,研究结果对空-地多源数据融合进行建筑物精细建模提供可靠的技术支持。  相似文献   
159.
多尺度合成的降水临近预报技术   总被引:3,自引:1,他引:2  
王珏  张家国  万玉发 《气象科技》2008,36(5):524-528
基于我国新一代多普勒天气雷达观测资料,以梅雨锋等大范围降水为主要研究对象,研究了降水临近预报方法.根据暴雨回波的多尺度特征等,研究暴雨回波的尺度滤波,分割、匹配等处理技术;根据不同尺度回波生命史来约束其预报时效,得到分尺度下的降水预报场,实现暴雨回波多尺度的合成降水量临近预报;将分尺度与不分尺度降水预报结果进行了比较.结果表明,针对大范围强降水多尺度合成的降水量临近预报方法,因不同尺度的回波外推考虑了各自运动的特性及其生命史的差异,预报精度有所提高.  相似文献   
160.
基于变异系数权重的灰色关联投影法在水质评价中的应用   总被引:1,自引:0,他引:1  
王芸 《地下水》2010,32(2):61-63
运用灰色系统理论和矢量投影原理,提出了灰色关联投影法,介绍了该方法的基本原理,给出了灰色关联投影角、灰色关联投影值等基本概念,总结了该方法进行系统分析的一般步骤。并将其应用于区域水环境质量综合评价当中,结果表明:该方法对于水质评价是有效可行的。  相似文献   
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