面向对象的时空概念建模方法   总被引：4，自引：0，他引：4  

张山山 《武汉大学学报(信息科学版)》2003,28(2):191-196

在面向对象技术的基础上，把地理信息的时空特征与对象模型融合到一起，产生了语义丰富的时空扩展对象模型，以支持包含时空信息的系统需求分析和设计。  相似文献   

虚拟加工环境中的工件动态建模方法研究   总被引：5，自引：0，他引：5  

罗亚波  陈定方  肖田元 《武汉大学学报(信息科学版)》2003,28(2):238-241

提出并实现了基于平面纹理映射的基元立方体构造方法，以之为动态结点建立了动态八叉树结构，实现了支持变精度动态建模的自相似递归算法。该算法确保离正在加工的部位更近的区域有更高的精度，并采用C^ Builder和OpenGL构造了一个集成于虚拟加工环境的可加工工件模型。  相似文献   

河北省粮食生产发展趋势及其地区差异   总被引：8，自引：1，他引：8  

吴凯  袁璋  许越先 《地理科学进展》2003,22(5):499-506

河北省2002年粮食作物播种面积为6484.4千hm2,其中小麦占37.8%,玉米39.7%;粮食、棉花、油料的种植比例为15.9:1.0:1.6。北部四地市粮食播面占全省的23.3%,南部七地市76.7%。2002年粮食总产2435.8万t,为1949年的5.2倍;粮食单产3756kg/hm2,为1949年的5.8倍;人均粮食362kg,为1949年的2.4倍。北部地区粮食总产占全省的17.2%,南部地区82.8%。据回归分析与双向差分建模分析,2010年粮食总产可达3087.5万t,粮食单产4478kg/hm2,人均粮食460kg。据灰关联分析,影响粮食总产的主要因子有:粮食单产、农副产品收购价格总指数(1978年=100)、农业机械总动力、农村用电量、农田化肥施用量与有效灌溉面积等。根据笔者预测,若2010年农业机械总动力达8989万kw,农村用电量240.8亿kwh,农田化肥施用量356.1万t,有效灌面4549.2千hm2,则其粮食单产可达4664kg/hm2;若2010年仍保持2000年小麦播面所占比例(0.387),玉米播面所占比例达0.439,则其单产可达4387kg/hm2。  相似文献   

新疆西达里亚T-II油藏储层三维建模研究     

邱立伟  李红雯  康志江 《新疆地质》2003,(2)

在新疆西达里亚T-Ⅱ油气藏的储层表征研究中,首先进行了地质及测井解释,在此基础上应用地质统计学方法进行了三维储层地质建模,建模过程中采用先建立砂层格架,再建立属性参数的“两步建模”研究思路,理论上减少了砂体与属性参数的解释矛盾与误差,提高了属性模型精确度.通过实际生产动态对属性模型进行检验,证明建模结果是正确的.  相似文献   

Fractal and Multifractal Modeling of Hydrothermal Mineral Deposit Spectrum： Application to Gold Deposits in Abitibi Area, Ontario, Canada   总被引：2，自引：0，他引：2  

ChengQiuming 《中国地质大学学报(英文版)》2003,14(3):199-206

A number of fractal/multifractal methods are introduced for quantifying the mineral de-lmsit spectrum which include a number-size, grade-tonnage model, power spectrmn model,multi-fractal model and an eigeavalue spectrmn model The first two models characterize mineral deposits spec-tra based on relationships among the measures of mineral deposits.These include the number of deposits,size of deposits,concentration and volume of mineral deposits.The last three methods that deal with the spatial-temporal spectra of mineral deposit studies are all expected to be popularized in near future.A case study of hydrothermal gold deposits from the Abitibi area,a world-class mineral district is used to demonstrate the principle as well as the applications of methods proposed in this paper,It has been shown that fractal and multifractal models are generally applicable to modeling of mineral deposits and occurrences.Clusters of mineral deposits were identified by several methods including the power spectral eral deposits in the Timmins and Kirkland Lake camps.  相似文献   

Theoretical Study on Stochastic Modeling of Combined Gravity-Magnetic-Electric-Seismic Inversion and Its Application     

YanHanjie YanHong LiYunping ZhangXiaofeng 《中国地质大学学报(英文版)》2003,14(3):227-233

As gravity field,magnetic field,electric field and seismic wave field are all physical fields,their object function,reverse function and compound function are certainly infinite contiuously differentiable func-tions which can be expanded into Taylor (Fourier) series within domain of definition and be further reduced in-to solving stochastic distribution function of series and statistic inference of optimal approximation,This is the basis of combined gravity-magnetic-electric-seismic inversion built on the basis of separation of field and source gravity-magnetic difference-value(D-value)trend surface,taking distribution-independent fault sys-tem as its unit,depths of seismic and electric interfaces of interests as its corresponding bivariate compound re-verse function of gravity-magnetic anomalies and using high order polynomial(high order trigonometric func-tion)approximating to its series distribution,The difference from current dominant inversion techniques is that,first,it does not respectively create gravity-seismic,magnetic-seismic deterministic inversion model from theoretical model,but combines gravity-magnetic-electric-seismic stochastic inversion model from stochastic model;second,after the concept of equivalent geological body being introduced,using feature of independent variable of gravity-magnetic field functions,taking density and susceptibility related to gravity-magnetic func-tion as default parameters of model,the deterministic model is established owing to better solution to the con-tradictioc of difficulty in identifying strata and less test analytical data for density and susceptibility in newly explored area;third,under assumption of independent parent distribution,a real modeling by strata,the prob-lem of difficult plane closure arising in profile modeling is avoided,This technology has richer and more detailed fault and strata information than sparse pattern seismic data in newly explored area,successfully inverses and plots structural map of Indosinian discontinuty in Hefei basin with combined gravity-magnetic-electric-seismic inversion,With development of high precision gravity-magnetic and overall geophysical technology,it is certain for introducing new methods of stochastic modeling and computational intelligence and promoting the develop-ment of combined gravity-magnetic-electric-seismic inversion to open a new substantial and promoting the develop-ment of combined gravity-magnetic-electric-seismic inversion to open a new substantial path.  相似文献   

飞行物体虚拟环境仿真系统的研究   总被引：2，自引：0，他引：2  

管华  王双亭等 《测绘学院学报》2003,20(1):29-31,38

概述了飞行物体虚拟环境仿真系统包含的主要技术，重点讨论了虚拟环境中视景系统构建的关键问题，如场景建模、模型驱动及视点的控制与变换等。  相似文献   

数学建模教学尝试     

陶诏灵 《气象教育与科技》2003,25(3):63-65

  相似文献   

3维地理信息系统：现状与展望     

朱国宾 《武测译文》1997,(4):13-19

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随机时变抗风结构动力可靠性分析     

韩光东  周家泽 《武汉测绘科技大学学报》1997,22(1):83-86

研究了随机时变结构特性，提出了随机时变强度的衰减表达式；在随机动力荷载作用下，用振型分解法 分析了时变参数结构的动力响应，得到了此类结构的动力学响 应谱与数字统计式；给出了确定时变界限的方法；提出了在役结构时变可靠度的分析方法，以及结构在设计使用期与预言使用期限内可靠度评估公式。  相似文献