模糊聚类分析及其地质应用实例     

唐淑贤 《湖南地质》1992,11(2):163-168

摘要聚类分析直接利用相似矩阵或相关矩阵来分类,但它们本身存在矛盾,分类时也会出现矛盾。为消除这个矛盾,可采用模糊聚类分析。它的特点是,通过相似矩阵连续自乘,改造成模糊分类矩阵,随后按不同要求进行分类。本文旨在介绍模糊聚类分析的步骤和方法,并提供一个PC—1500袖珍机模糊聚类分析源程序。附两个算例。  相似文献   

黄河下游的河性   总被引：8，自引：0，他引：8  

尹学良  陈金荣 《地理学报》1992,47(3):193-207

本文探讨了黄河一般特性的综合关系,讨论了河道演变中均衡与非均衡的问题、滩槽冲淤的利与害和主与从的问题,同时讨论了河道冲淤演变特性、与水沙条件的关系、河槽淤积率和淤积比等。  相似文献   

The perimeter-area fractal model and its application to geology   总被引：14，自引：0，他引：14  

Qiuming Cheng 《Mathematical Geology》1995,27(1):69-82

Perimeters and areas of similarly shaped fractal geometries in two-dimensional space are related to one another by power-law relationships. The exponents obtained from these power laws are associated with, but do not necessarily provide, unbiased estimates of the fractal dimensions of the perimeters and areas. The exponent (D_AL) obtained from perimeter-area analysis can be used only as a reliable estimate of the dimension of the perimeter (D_L) if the dimension of the measured area is D_A=2. If D_A<2, then the exponent D_AL=2D_L/D_A>D_L. Similar relations hold true for area and volumes of three-dimensional fractal geometries. The newly derived results are used for characterizing Au associated alteration zones in porphyry systems in the Mitchell-Sulphurets mineral district, northwestern British Columbia.  相似文献   

Moment tensors of earthquakes in and near the Tibetan Plateau and their scaling law     

Si-Hua Zheng  Ziro Suzuki 《地震学报(英文版)》1993,6(2):365-377

Moment tensors of eleven major earthquakes in the Tibetan Plateau and its surrounding region from 1966 to 1980 are estimated by generalized inverse technique. The seismic source time function and focal depth are immediately determined in the inversion. The results show that moment tensors of some events differ significantly from double couple, the deviation increases with decreasing plunge angle of null axis. All these events occurred in the upper crust, much shallower than those reported so far, for example, in NEIS Bulletin. Focal mechanism solution obtained from the moment tensors are consistent with the idea that the Indian plate collides northwards with the Eurasian plate and that an eastward spreading exists in the crust of the Tibetan Plateau. The stress drops for earthquakes of intraplate are systematically higher than those of earthquakes in suture zone. The source process duration becomes longer with seismic moment, but for the same seismic moment, the process duration for earthquakes in suture zone is about 1.4 times of those for intraplate event, these results suggest that the earthquakes near suture zone may be of a special characteristics in source process differently from those in intraplate. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 423 – 434, 1992.  相似文献   

既找矿又开矿搞活地勘单位：赴疆考察的认识和体会     

张攀华 《湖南地质》1993,12(2):70-74,79

“六五”和“七五”期间,新疆地矿局强化了地质找矿的科学管理,充分发挥了地质科技在找矿中的先导作用,争取到了一个好的外部环境,取得了地质找矿的重大突破。他们既找矿又开矿,以找矿促开发,走找矿与开矿结合的道路,实行探、采、工、贸一体化,创造了搞活地勘单位,振兴地方经济的成功经验。  相似文献   

流域物质与水系及产沙间非线性关系实验研究   总被引：7，自引：0，他引：7  

金德生  陈浩  郭庆伍 《地理学报》2000,55(4):439-448

在３５．５６ｍｍ／ｈ．ｃｍ＾２定雨强的人工降雨条件下,组成物质中径分别为０．０２１ｍｍ、０．０６６ｍｍ及０．０７６ｍｍ的发育对比实验表明,产沙过程具有波动振荡衰减特征;水系发育以增加河道（沟道）数目及弯曲拉伸长度两种方式进行最小消能。水系分形维数正是这种消能的量度。水系分数维值随时间呈不对称上凹型曲线。对比分析表明：产沙过程的振荡性、衰减率,随物质变粗而加强,水系河道数目随物质变细而增多,河道随物  相似文献   

线与线之间的空间拓扑关系组合推理   总被引：4，自引：0，他引：4  

郭庆胜  刘小利  陈宇箭 《武汉大学学报(信息科学版)》2006,31(1):39-42

在空间拓扑关系组合描述的基础上，进一步完善了利用基本空间拓扑关系进行组合推理的方法。并建立了组合表。详细绘制了两条线之间的空间拓扑关系图。  相似文献   

Seismic hazard assessment for derivation of earthquake scenarios in Risk-UE     

Ezio Faccioli 《Bulletin of Earthquake Engineering》2006,4(4):341-364

The main features of the Risk-UE project approach to assessing the ground-shaking (and related hazards) distribution within urban areas are described, as a basis for developing seismic damage scenarios for European cities. Emphasis was placed in the project on adoption of homogeneous criteria in the quantitative treatment of seismicity and in constructing the ground-shaking scenarios, despite wide differences in amount and quality of data available for the cities involved. The initial steps of the approach include treatment of the regional seismotectonic setting and the geotechnical zonation of the urban area, while the hazard assessment itself takes the form of both a deterministic analysis, and of a probabilistic, constant-hazard spectra analysis. Systematic 1D site response analyses were used, mostly in the softer soil zones, to modify (when needed) the obtained ground motion maps. Earthquake induced hazard effects, such as liquefaction and landsliding, are also briefly dealt with at the end.  相似文献   

浙江及邻区尾波Q值研究   总被引：8，自引：3，他引：8       下载免费PDF全文

朱新运  张帆 《地震工程学报》2006,28(2):108-113

基于单次散射(Aki)模型,利用2000年至今浙江及安徽台网记录的37次ML3.0以上地震的数字地震波资料,计算了浙江及邻近省区平均尾波Q值,并拟合了Q值对频率的依赖关系数据。结果为:Q(f)=212±33.5f0.62±0.11,与国内其它区域相比,本区域为Q值高值、对频率低依赖性区域。认为本研究区内构造活动弱,地震活动水平低。本文就Q值对频率、尾波窗长等的依赖性特征及影响Q值计算的噪声水平、滤波器、数据采样等因素进行了深入分析。  相似文献   

地震安全性评价工程师资格考试大纲已审定通过   总被引：12，自引：0，他引：12  

本刊讯 《震灾防御技术》2006,1(3):217-217

把美国西部地区作为参考区,采用我国地震动参数区划图工作时所使用的美国西部地区强震资料建立参考区水平向基岩短周期加速度反应谱衰减关系;采用美国南加州地区数字宽频带记录建立参考区水平向基岩长周期加速度反应谱衰减关系。与由丰富的等震线资料统计得出的我国东部地区和西部地区的地震烈度衰减关系一起,用转换方法分别得到了我国东部和西部地区水平向基岩加速度反应谱衰减关系。对该衰减关系在重大工程地震安全性评价工作中的应用提出了建议。  相似文献