Modeling spatiotemporal topological relationships between moving object trajectories along road networks based on region connection calculus     

Linbing Ma  Jing Wu  Qiliang Liu 《制图学和地理信息科学》2016,43(4):346-360

Considering the attempts to model spatiotemporal topological relationships between moving object trajectories, the conceptual and computational framework for moving objects along a road network has not received much attention. This paper aims to draw an improved model based on Region Connection Calculus (RCC) theory to represent the spatiotemporal topological relationships between moving object trajectories along road networks. This paper first uses a dimension reduction method based on a linear-reference transformation to model the moving object trajectories segments, and then defines new time–connection and space–connection relations between two trajectory segments. On this basis, the paper proposes an extension to the RCC-based spatiotemporal binary relationship set so that the combined semantics of the spatiotemporal predicates can be described completely. A case study was carried out using Floating Car Data in Guangzhou city. The computational results show that in a real application, the occurrence frequencies of the RCC-based binary relationships are distributed nonuniformly and the semantics of some binary relationships with the highest occurrence are coarse. Therefore, the partition of the spatiotemporal connection relations and the finer aspects of the spatiotemporal relationship model may require further research work.  相似文献   

Upper bound limit analysis of uplift failure in pressurized sealed rock tunnels          下载免费PDF全文

P. Perazzelli  G. Anagnostou 《国际地质力学数值与分析法杂志》2018,42(5):719-735

The rock around tunnels used for gas storage is subject to high pressures, reaching 30 MPa in the case of compressed air energy storage. Uplift failure of the overlaying rock mass up to the surface represents the main hazard scenario in such cases. The present paper investigates this problem by using the upper bound theorem of limit analysis assuming a continuum rock mass model obeying the Mohr Coulomb failure criterion with tension cut‐off. Tools of the calculus of variations are used to assess the geometry of the failure surface. The effects of geometrical and geotechnical parameters on uplift pressure are analyzed systematically. Charts are then provided, which enable a quick estimation of the upper bound of uplift pressure across a wide range of geotechnical and geometrical conditions.  相似文献   

探地雷达目的体物理模拟研究结果   总被引：34，自引：0，他引：34  

王惠濂 《地球科学》1993,18(3):266-284

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Ground stress determinations in Canada     

G. Herget 《Rock Mechanics and Rock Engineering》1974,6(1):53-64

SummaryGround Stress Determinations in Canada Stress determinations with the biaxial (Doorstopper) and the triaxial strain cell of the C. S. I. R., South Africa, are discussed and show that the triaxial cell is the more desirable instrument if good rock conditions exist. Vertical and average horizontal stresses in Canada are similar in magnitude to those from other parts of the earth's crust and show that vertical stresses are related to weight of overburden and average horizontal stresses increase in most of the cases with 0.407 kg/cm² per metre of depth. More data are necessary to make any prediction for the average horizontal stress beyond a depth of 800 m.Stress determinations and a tectonic analysis show that the unravelling of the geological stress-strain history allows some prediction of principal stress directions, but the attached uncertainties due to gaps in documentation require proof by stress determinations.With 8 Figures  相似文献   

神农架松柏镇水文地球化学研究     

程胜高  马腾  周建兰 《矿物岩石地球化学通报》2004,23(2):140-143

近年来，神农架松柏镇居民的结石病时有发生．并有增长的势头。为了解地质环境尤其是饮用水对病患的影响，笔者现场对患病情况以及各种水源(包括河水、泉水、自来水)的来源、化学组成和放射性进行了调查，运用水质常规方法和原子吸收光谱分别测定了离子和微量元素。同时，与地质环境类似的木鱼镇进行了对比调查。研究结果显示，两地地表水、地下水的各种指标均未超出“生活饮用水水源水质卫生标准”。(CJ3020-93)，且松柏镇水体中的放射性(γ射线)低于木鱼镇，而居民的患病率却远高于木鱼镇，可见松柏镇的水环境与居民的结石病无直接关系。  相似文献   

Hydrogeochemical Characteristics of Shennongjia Forest District at Songbai Town, Hubei     

程胜高  马腾  周建兰 《中国地球化学学报》2004,23(2):191-196

1IntroductionSongbaiTown—thecapitaloftheShengnongjiaforestdistrictisthecenteroflocalpolitics,eco nomicsandculture ,anditisalsoanimportanttourismbase.Butinrecentyears,thelocalinhabi tantsinthisareahavesufferedfromcalculusdiseaseoccasionallyandthediseaseseemstobeofmoreandmorefrequentoccurrence .Thisnotonlycausesmasspanicandinfluencesnormalworkandstudyofthelocalpeople ,butalsobringsaboutnegativeeffectsontouristindustryofthisareaandrestrictsthedevelopmentoflocaleconomy .Inordertounderstandthesta…  相似文献   

具有分数Kelvin模型的粘弹性岩体中水平圆形硐室的变形特性   总被引：19，自引：0，他引：19  

刘林超  张卫 《岩土力学》2005,26(2):287-289

在忽略体积变形的情况下进行水平图形硐室变形特性研究,建议采用分数代数Kelvin本构关系模拟岩体的粘弹性,提出了一种分析粘弹性岩体中水平圆形硐室变形特性的新思路,讨论了硐室位移及应变随时间变化的规律并与经典的Kelvin模型进行了比较。从分析的结果表明,分数代数能很好地模拟出粘弹性体松驰特性,通过改变分数代数的阶数又可以模拟各种粘弹性岩体、比经典粘弹性模型具有更大的适用范围。  相似文献   

基于分数阶滤波器的遥感图像处理     

郭丁  顾行发  余涛  赵辉  马红涛 《国土资源遥感》2011,22(1):48-51

在研究分数阶微积分的基础上,提出了一种基于WLS误差准则的滤波方法,该滤波器的系数可通过调节其阶次来改变; 给出了该滤波器的原理,分析了其幅频特性.通过用Riemann-Liouville定义验证,并将此滤波器运用于遥感图像处理,结果表明,该方法在抗干扰和提取更多细节方面取得了很好的平衡,具有较好的滤波效果.  相似文献   

裂隙土等效连续介质的渗透张量及表征单元体积   总被引：1，自引：0，他引：1  

李锦辉  张利民  雷卫东 《地震工程学报》2011,33(Z1)

裂隙土的渗透特性是裂隙土边坡稳定性分析中重要的参数。文中通过分别考虑随机裂隙网络和土体本身的渗透性,推导裂隙土的渗透系数,并用张量的形式表示渗透系数的各向异性。同时建立了确定裂隙土表征单元体积的准则,为应用等效连续介质模型提供了基础。结果表明裂隙土的渗透系数大于裂隙网络和土体的渗透系数,其渗透方向取决于裂隙网络的渗透方向。算例中裂隙土的表征单元体积大约是裂隙长度平均值的5倍。  相似文献   

TENSORIAL RESOLUTION:A DIRECT TRILINEAR DECOMPOSITION   总被引：4，自引：0，他引：4  

EUGENIO SANCHEZ~ BRUCE R.KOWALSKI Laboratory for Chemometrics Department of Chemistry BG-.University of Washington  Seattle WA  U.S.A. Mobil Research  Development Corporation  Paulsboro Research Laboratory  Billinsport Ro  Paulsboro  NJ  U.S.A. 《地理学报(英文版)》1990,(1)

Modern instrumentation in chemistry routinely generates two-dimensional(second-order)arrays of data.Considering that most analyses need to compare several samples,the analyst ends up with a three-dimensional(third-order)array which is difficult to visualize or interpret with the conventional statisticaltools.Some of these data arrays follow the so-called trilinear model,(?)These trilinear arrays of data are known to have unique factor analysis decompositions which correspondto the true physical factors that form the data,i.e.given the array (?),a unique solution can be found inmany cases for each order X,Y and Z.This is in contrast to the well-known second-order bilinear datafactor analysis,where the abstract solutions obtained are not unique and at best cannot be easilycompared with the underlying physical factors owing to a rotational ambiguity.Trilinear decompositions have had the disadvantage,however,that a non-linear optimization withmany parameters is necessary to reach a least-squares solution.This paper will introduce a method forreducing the problem to a rectangular generalized eigenvalue-eigenvector equation where the eigenbectorsare the contravariant form(pseudo-inverse)of the actual factors.It is shown that the method works wellwhen the factors are linearly independent in at least two orders(e.g.X_(jr),and Y_(jr) are full rank matrices).Finally,it is shown how trilinear decompositions relate to multicomponent calibration,curve resolutionand chemical analysis.  相似文献